Well that's not supposed to happen.

Microsoft formally released Internet Explorer 8 last Thursday, an event that arrived armed with a full media blitz and several glowing reviews. Normally the release of an upgrade like that would result in millions of installations and market share immediately skyrocketing, but that's not what happened.

According to Net Applications, which monitors browser usage in near-real-time, IE8's overall share of the browser market had climbed to 2.59 percent by Sunday... but then dropped Monday morning, down to 1.86 percent.

The reason for the decline is fairly obvious, as InformationWeek notes:
"Early adopters of IE8 are switching back to the more familiar, and -- at this point -- reliable Explorer 7 browser."

Compatibility is obviously the big problem, with legions of comments piling up on message boards and blog posts about websites that are totally broken by the browser's new implementation of "standards." Messed-up design isn't the only issue, either. Some users report that IE crashes with an error during certain applications, like printing.

Of course, IE8's fortunes mirror Internet Explorer's long trend down, having dropped from 75% market share to 67% in the last 12 months, again according to Net Applications. (Alternate statistics show a much grimmer view for IE.)

But one commenter offers an alternate explanation for IE8's Monday surprise, suggesting that corporate users forced to use IE6 and IE7 add to the market share of those browsers during weekdays, and that the weekend jump for IE8 (and all other browsers) is stastically explainable that way. Interesting theory...