The reason is a noncompete Miller (pictured here) signed, part of a severance agreement he reached with the media giant after it unceremoniously tossed him out in late 2006.

A Time Warner spokesman said Miller was barred from working “for a variety of competitors, including Yahoo, until March of 2009.”

Like it matters.

According to sources at Time Warner (TWX), the decision came from on high at corporate and not from the AOL unit. And it is not due to jealousy over attention Miller has received of late–Microsoft was also interested in hiring him to take over for departing exec Kevin Johnson.

Miller, sources said, was called by Time Warner CEO Jeff Bewkes (pictured here) last night and told by him, “We’ve changed our mind.”

Why?

Well, to be sure, Miller is no Time Warner favorite, even after being gone for almost two years.

But Miller, whom Time Warner and AOL execs never miss an opportunity to bash, off the record, is also no threat to AOL, which he actually helped revive from the ruins of the disastrous AOL-Time Warner merger.

While working on my second book about AOL in 2002, I will always remember visiting Miller at AOL HQ in Dulles, Va.–where he took up residence in former AOL exec Bob Pittman’s office–and finding him unusually calm after he got the thankless job of following Pittman and AOL icon Steve Case.

Time Warner forces, in the form of new CEO Dick Parsons, had finally managed to take back control of the company and–in a fit of misguided pique–brought holy hell down on the AOL unit.

It was a profoundly emotional reaction, which cost Time Warner precious years and much, much money, as the Internet business revived itself and AOL largely sat on the sidelines.

Miller was in the unenviable position of cleaning up the mess, while also having to listen to endless griping from his bosses.

And, despite the line being put out by Time Warner, he did a pretty good job.

While he might have dumped the dial-up business sooner and been more of an organized manager (the two big complaints about him), Miller did strike AOL’s lucrative Google search ad deal and also bought Advertising.com. (He also tried to buy YouTube, to no avail.)

That purchase should be reason enough for Time Warner to erect a small altar to him, given that it is one of AOL’s only truly valuable assets and the reason Microsoft (MSFT) and Yahoo (YHOO) have been interested in possibly buying the unit.

But no.

Instead, there is the usual he-said-she-said wrangling about whether Miller got approval for being let out of the noncompete clause.

Time Warner apparently claims Miller never got an official waiver, and Miller forces say Bewkes okayed the issue weeks ago, when it was first announced that Miller was one of the board picks being put forth by activist investor Carl Icahn.

It defies belief to go with Time Warner version, given everyone and their mother’s mother knew Miller was the likely pick of both Icahn and, especially, Yahoo CEO Jerry Yang.

More interesting is why Time Warner would choose to speak now, especially on the day of Yahoo’s board meeting.

At the meeting, the Yahoo board approved expanding its number of directors from 9 to 11 and formally voted to let Icahn take over the seat being vacated by Robert Kotick.

Miller was the shoo-in, with other likely choices. including former Nextel (S) exec John Chapple, media exec Frank Biondi and former Grey Global Advertising head Edward Meyer.

Perhaps Bewkes imagines somehow that Miller will be a leverage point in talks Time Warner has been having with Yahoo to be acquired. But the smooth exec is an expert negotiator and that seems unlikely.

More likely is that those talks, like AOL’s talks with Microsoft, have gone a little cold of late as everyone shuts up and stops making ill-conceived moves, to show Wall Street that they have their forward-leaning Internet strategies figured out.

No one does. Not Yahoo. Not Microsoft. And, most definitely, not Time Warner’s AOL.

That’s why Bewkes should stop the saber-rattling and free Miller to serve on the Yahoo board.

Yahoo could benefit and, as it stands now, Time Warner just looks silly–it does not want Miller, but it doesn’t want anyone else to have him.

My three-year-old knows how to share better than that.

After its annual meeting today, as its board members had lunch together, Yahoo released the results of its shareholder vote and it seems we will still have CEO Jerry Yang to kick around some more.

Yang garnered 85.4 percent of the shares to stay on as a director of the Internet company, with 14.6 percent withheld.

While having almost 15 percent of your investors think you are not worthy is not good, it is also not nearly as bad as it could have been.

In fact, overall results are actually better than last year. Thus, being attacked by Microsoft (MSFT) and activist investor Carl Icahn has had a dulcet effect on Yang’s image.

Yahoo Chairman Roy Bostock fared worse, grabbing only 79.5 percent of the yes vote, with 20.5 percent withheld.

Yahoo (YHOO) stockholders dinged three outside proposals: a pay-for-superior-performance principle for executive compensation, the establishment of policies on Internet censorship, and the creation of a board committee on human rights.

The board also officially put Icahn in the seat vacated by Activision (ATVID) CEO Robert Kotick (whose vote was among the best, ironically, with 92.4 percent for and 7.6 percent withheld).

It also expanded the board to 11 from 9, but will not announce the two new members until Aug. 15.

Former AOL head Jon Miller, who was one of the likely picks, is apparently being blocked by Time Warner via a noncompete agreement. Miller was bounced from AOL some years ago.

Miller was called directly by Time Warner (TWX) CEO Jeff Bewkes last night, sources said, and was told by Bewkes, “We’ve changed our mind.”

More on this idiotic development from the AOL owner next.

Until then, here are the pertinent stats on the Yahoo vote:

Roy J. Bostock (Shares for: 832,023,657/79.5%; Shares Withheld: 214,071,927/20.5%)

Ronald W. Burkle (849,373,291/81.2%; 196,722,293/18.8%)

Eric Hippeau (948,862,579/90.7%; 97,233,005/9.3%)

Vyomesh Joshi (971,594,650/92.9%; 74,500,934/7.1%)

Arthur H. Kern (814,871,925/77.9%; 231,223,659 /22.1%)

Robert A. Kotick (967,044,818; 92.4%; 79,050,766/7.6%)

Mary Agnes Wilderotter (964,939,727/92.2%; 81,155,857/7.8%)

Gary L. Wilson (856,006,576/81.8%; 190,089,008/18.2%)

Jerry Yang (893,055,602/85.4%; 153,039,982/14.6%)

The annual gathering of tech and media luminaries was created and is run by my partner Walt Mossberg and me.

D6 tech and media speakers include: Microsoft Bill Gates and Steve Ballmer of Microsoft (MSFT); News Corp.’s (NWS) Rupert Murdoch; Jeff Bewkes of Time Warner (TWX); Mark Zuckerberg and Sheryl Sandberg of Facebook; Michael Dell of Dell Computer (DELL); IAC’s (IACI) Barry Diller; Amazon’s (AMZN) Jeff Bezos; Howard Stringer of Sony (SNE); and TiVo’s (TIVO) Tom Rogers.

Also: Tom Glocer of Thomson Reuters (TRI); Melinda Gates of the Gates Foundation; FCC Chairman Kevin Martin; Lowell McAdam of Verizon Wireless (VZ); Activision’s (ATVI) Robert Kotick; and former Microsoft tech guru Nathan Myhrvold of Intellectual Ventures.

Just recently, we added Jerry Yang, CEO and co-founder of Yahoo (YHOO), and now he is being joined onstage at the conference by Yahoo President Sue Decker (pictured here in a lovely Wall Street Journal dot-drawing).

The pairing should make for a lively session, given all the heat around Yahoo of late, largely related to the scuttled attempt by Microsoft to buy the company.

What would you like to know about that and anything else about Yahoo?

As it so happens, you can ask!

While the conference is sold out, you can submit questions that you would like answered to Yang and Decker or any of the speakers via text or video. Walt and I will pick the best ones and let loose.

Ask early and often here!

In addition, the whole conference will be online at AllThingsD during the conference, via live blogs and reports of breaking news (and there will be breaking news, as there always is), along with video highlights.

And videos of all the interviews will be posted soon after it is over.

Bill Gates and Steve Ballmer of Microsoft (MSFT). News Corp.’s (NWS) Rupert Murdoch. Jeff Bewkes of Time Warner (TWX). Yahoo’s (YHOO) Jerry Yang.

All of them engaged in roiling Internet deal-making of late and all of them in just three weeks on the same stage–but not, thankfully, at the same time, or we’d need a professional negotiator–at the 6th D: All Things Digital conference in Carlsbad, Calif.

The annual gathering of tech and media luminaries was created and is run by my amazing partner Walt Mossberg and me (see us here at D5) and will take place May 27 to 29.

The conference, as we describe it on our Web site, is “unlike any other executive conference.” What we mean by that is that we try to determine the next direction of the digital revolution via unscripted and informal, but pointed, conversations about the impact of digital technology with industry leaders.

In other words, Walt and I needling at the major players of the digital sector, until they give up the good stuff.

The other digital and media leaders coming? That would be: Mark Zuckerberg and Sheryl Sandberg of Facebook; Michael Dell of Dell Computer (DELL); IAC’s (IACI) Barry Diller; Amazon’s (AMZN) Jeff Bezos; Howard Stringer of Sony (SNE); and TiVo’s (TIVO) Tom Rogers.

Also: Tom Glocer of Thomson Reuters (TRI); Melinda Gates of the Gates Foundation; FCC Chairman Kevin Martin; Lowell McAdam of Verizon Wireless (VZ); Activision’s (ATVI) Robert Kotick; and former Microsoft tech guru and Nathan Myhrvold of Intellectual Ventures.

To say our timing is impeccably planned would be undeserved–we had no idea so much news related to all these companies and their leaders would break out, from the tough economy to takeover battles to court face-offs to mergers to trying to create a whole new way of reading.

Also, there will be some–as yet under wraps–amazing demos onstage too.

While the analog conference has been sold out for many months, the action will be on the AllThingsD.com site throughout the conference with round-the-clock live blogging by Digital Daily’s John Paczkowski, as well as video highlights from stage.

In addition, we’ll be pointing all over the Web to important tech and media news that breaks at D6.

And we will also stream the entire conference in the weeks after the conference takes place, so ATD’s audience can experience the whole thing, even if they cannot all attend.

But anyone’s questions can be there, though–this year, you can submit questions to any of the speakers via text or video that you would like answered. Walt and I will pick the best ones and let loose. Ask early and often here!

Walt and I are very excited for D6, even after last year, when we brought together industry legends Bill Gates and Apple’s Steve Jobs, for an historic joint interview.

At the time, Walt and I joked that we would not be able to top that amazing event (the video of the entire interview is below).

That interview was nearly unbeatable, but we also think that with the top-level interviewees we have assembled for D6, that it is game on.

Until then, here’s the Gates/Jobs video from D5:

First stop, obviously, is Yahoo, which reports its fourth quarter and also full-year earnings (and also perhaps some board-approved layoffs) tomorrow after the markets close.

With everything from consistently persistent takeover rumors, a still-lagging stock price and continued scrutiny on its moves to revive itself, the company’s managers and–it must be assumed–its directors obviously face challenges in the year ahead.

They certainly seem to be a pretty experienced group, with just the right kind of expertise in retail, telecommunications, engineering and entertainment.

Curiously, with all the noise around Yahoo, this has been a circumspect bunch and it’s not clear how much influence this group is exerting over management or how willing it is to roll up its sleeves and get into it.

Still, board members are supposed to be where the buck actually does stop, so, as a BoomTown public service, here’s a little primer of who’s who on the Yahoo BOD, so you know who is actually in charge (and, of course, who is to blame):

First among equals is obviously Yahoo CEO and Co-Founder Jerry Yang, who needs no introduction. Born in Taiwan and raised in San Jose, Calif., he has been trying to bring back the company he founded with David Filo since taking over the top slot at Yahoo last June. The obviously iconic figure within the company, he occupies the hottest seat of all. Some think his leadership has not been nearly bold enough, while others think his steadier approach to Yahoo’s revival is just what the company has needed.

Terry Semel served as Yahoo CEO from 2001 to 2007. After he left that job when the company’s troubles became more pronounced (to be fair, Semel did do a great job getting Yahoo back from its last brink when the first bubble popped), the former Hollywood mogul kept his title as chairman. He is also on the board of Polo Ralph Lauren, as well as many arts and cultural organizations. Recently, Semel revived his Los Angeles-based new media investment firm, Windsor Media, and rumors abound to his intentions–including possibly making a play for a Hollywood studio. Big question: Will Semel continue as chairman of Yahoo in 2008?

What to make of Roy Bostock, who has been on Yahoo’s board since 2003? I’ll tell you what: If Semel were to step down as chairman, the chatter is that the former top-level advertising exec (chairman and chief executive officer of D’Arcy Masius Benton & Bowles) is best suited to the job, given the importance of Yahoo’s ad business. Bostock also serves now has chairman of Northwest Airlines and is on the board of Morgan Stanley and is a principal at Sealedge Investments LLC.

Ron Burkle, founder and managing partner of the Yucaipa Companies, a private investment firm, has been a director since 2001. The high-profile Burkle, of course, is better known for being best billionaire buddy of Bill Clinton (and big fundraiser for Hillary Clinton). He is a curious choice to be on the board, although he is said to add an interesting perspective and also has obvious experience in retail and distribution (largely in the supermarket industry). He is also on the boards of Occidental Petroleum and KB Home.

Vyomesh Joshi joined the Yahoo board in 2005. He probably brings a good consumer product perspective to the company from his perch as executive vice president of the Imaging and Printing Group at Hewlett Packard, a $26 billion business with an operating profit of $3.8 billion, which is a whole lot of the kind of ink Yahoo needs. The longtime HP exec also has responsibilities in the entertainment arena for HP, which should be a boon to Yahoo.

The same goes for Robert Kotick, the chairman and CEO of games maker Activision, which recently merged with Vivendi’s Blizzard Entertainment unit, to create one of the biggest gaming companies in the world. Yahoo could use a little Guitar Hero buzz that Kotick’s company has gotten from the third version of the popular interactive game, a big holiday success, and also Blizzard’s World of Warcraft.

The other Northwest Airlines link is its Chairman Emeritus Gary Wilson, who has been on the Yahoo board since 2001. Wilson, who is also on the board of CB Richard Ellis, has an extensive financial background, working as the top numbers guys at places like Walt Disney (where he was a longtime board member) and Marriott. But can he lend his expertise to make the numbers work better at Yahoo?

The only woman director, Maggie Wilderotter, joined last July and serves as the chairman and CEO of Citizens Communications, which is an independent provider of telecommunications services. That background is important for Yahoo, but perhaps more important is her experience as a SVP at Microsoft (rumored to be the main company interested in acquiring Yahoo). Wilderotter has also been president and CEO of Wink Communications and has held a number of jobs at AT&T, and serves on the board of Xerox and the Tribune Company.

Eric Hippeau, managing partner at Softbank Capital Partners, is one of the two granddaddy Yahoo board members (along with Arthur Kern), having served as a director since 1996. Before Softbank, he was chairman and CEO of Ziff-Davis in its heyday. Hippeau is also on the board of Starwood Hotels and Resorts Worldwide.

Arthur Kern has also been on the Yahoo board since 1996. Kern made his fortune selling off American Media, an owner of radio stations, which he co-founded and ran. Kern now invests in marketing and media companies. (BoomTown, with great regret, has never met him after all these years–lazy, lazy BoomTown! And everyone says how nice he is. Lunch, Arthur?)

Ed Kozel, the CEO of the start-up Skyrider (a P2P search engine), is perhaps the most experienced technologist on Yahoo’s board and another key member of the board, say many, where he has served since 2000. He’s been a VC (Open Range Ventures), a consultant (Integrated Finance) and also was a longtime Cisco exec (he was CTO and SVP of business development there) and board member. He’s also been on the board of Reuters and is a director for Network Appliance.