http://bugs.winehq.org/show_bug.cgi?id=31934
--- Comment #3 from aaron orion@parsed.net 2012-10-12 12:24:00 CDT --- (In reply to comment #1)
This is supposedly fixed in the latest beta drivers.
Confirming this is fixed upstream with drivers 12.9beta.
Realistically though, you're probably better of running the Mesa drivers for anything except Southern Islands cards at the moment.
Comparing my usual usages, I still get much better results with fglrx, even with this bug present.