http://bugs.winehq.org/show_bug.cgi?id=26835
--- Comment #54 from Josh cheeseness@yahoo.com 2011-04-19 21:54:45 CDT --- (In reply to comment #52)
Just speculating, but that could be less to do with Wine and more to do with a potential Source engine update that came with Portal 2.
I have no problems with Portal 1, TF2 or L4D2. I don't believe that the recent Source engine updates are related to the problem we're chasing here.