http://bugs.winehq.org/show_bug.cgi?id=24064
--- Comment #41 from Jerome Leclanche adys.wh@gmail.com 2010-09-28 09:45:11 CDT --- (In reply to comment #40)
Valve fixed this issue on their side. It was their fault(GetMessageW forwarded to GetMessageA), although a wine implementation detail(GetMessageA calls GetMessageW) triggered the bug. Valve's bug could have caused issues on Windows too, in theory.
Please make sure your Steam client is up to date if you're still experiencing this issue.
My client is up to date; I can trigger the issue in Portal and Worms at least (haven't tested TF2 since the update). If you need any sort of log, ask away.