Apparently, according to Yahoo, Microsoft is as clever and deceptive as the buff and gun-toting Angelina Jolie in the new film “Wanted.”

BoomTown will get to that later. But with Yahoo (YHOO) stock hovering close to $20 a share, Microsoft (MSFT) has certainly got to be thrilled that the sweetened search-ad deal it is currently preparing–including forking over about $10 billion for one-third of the company–is getting cheaper by the minute.

With Yahoo’s stock at a disturbing $20.96 right now–and headed lower, it seems–its market value is only $28.4 billion, a depressed number that has sent its investors into a tizzy.

As I wrote last week, it’s those investors who are pushing Yahoo’s board to consider accepting a new version of Microsoft’s search-ad proposal that it turned down in favor of one from Google (GOOG) recently.

Those same investors had urged Microsoft to make a sweeter offer, promising a more cooperative Yahoo, especially now that it faces an upcoming proxy fight with billionaire Carl Icahn at its Aug. 1 board meeting.

Microsoft has no interest in swallowing Yahoo whole–although the dropping price does make it kind of tasty.

But it has been working on a beefed-up search deal, with more revenue guarantees on search ads and a higher price for search assets it would buy outright.

The centerpiece of the offer, of course, would be a deal to buy about one-third of Yahoo from existing shareholders at a premium to where it is trading now.

In its previous search-ad offer, Microsoft had offered to buy 16% of Yahoo for $8 billion at $35 a share.

Many large investors, disillusioned with the leadership of CEO Jerry Yang, have warned him and the board that they will vote with Icahn unless Yahoo engages with Microsoft and fast.

If Yahoo does change its mind and strike a sweeping search-ad deal with Microsoft, though, it would have to pay Google a $250 million fee for killing the deal.

Still, Yahoo took the opportunity today to ding Microsoft once again about its botched takeover battle, in a regulatory filing related to the proxy fight.

In the document, it called the software giant “unresponsive and inconsistent,” and noted “the record casts doubt on whether Microsoft was ever committed to a whole company acquisition.”

(See Yahoo’s slide on the issue below–click to make it larger)

Ooooh, it almost sounds like Yahoo is saying Microsoft carefully planned this intricate scheme to get Yahoo into this prone and disastrous position.

It’s almost as complicated as the plot of the thriller “Wanted”–BoomTown recommendation: Two thumbs up!–in which an office drone played by James McAvoy is whipped into deadly-assassin shape by a leather-clad Angelina Jolie and also badly tricked by her.

Yahoo’s leadership only wishes they had Angelina to kick them around.

Unfortunately for shareholders everywhere, they seem to be doing a very good job of it all by themselves.

As an added plus, here’s the “Wanted” trailer: