http://bugs.winehq.org/show_bug.cgi?id=12553
--- Comment #25 from Igor Tarasov tarasov.igor@gmail.com 2009-10-29 18:39:54 --- Everything from comment #23 is still here.
The entire problem is in wrong handling of button bitmap sizes. I've been trying to write a test that would illustrate that, but I couldn't:
http://www.mail-archive.com/wine-devel@winehq.org/msg54293.html