http://bugs.winehq.org/show_bug.cgi?id=27156
--- Comment #35 from 3vi1 winehq.org@eternaldusk.com 2011-05-29 08:53:33 CDT --- I can confirm what Evan said in #34.
While the problem has been significantly reduced, it does occasionally and randomly still seem to change where you're looking in Source games. I tested with L4D2 and the current git.