Skype just installed an update today that changed its behavior on Windows 7. You can’t close the Skype window without completely shutting Skype down. So you end up with the Skype icon in the system tray (where it belongs, so far as I’m concerned) and another icon in your Windows 7 task bar (where it has no business being when I’m not actively using it).
This isn’t a big deal. Except it’s been severely annoying me all day long. I tried fiddling with all sorts of Skype options and searching for Skype help, all to no avail. Finally I used what I should have tried first: Google. And near the top of the first results page there was a blog post from My Digital Life that fixed it immediately. In a nutshell, just run Skype in compatibility mode for an earlier version of Windows (I used Vista SP 2). And it will start working the way it always has, and that I think it always should.
Charles Engelke's Blog 