http://bugs.winehq.org/show_bug.cgi?id=10841
--- Comment #29 from Dmitry Timoshkov dmitry@codeweavers.com 2008-05-26 22:53:56 --- (In reply to comment #28)
It seems to happen to all apps that go fullscreen (such as games). I'm using Wine 1.0-rc2.
Have a look at the bug 10929 for a possible reason.