http://bugs.winehq.org/show_bug.cgi?id=21043
--- Comment #13 from Meho R. meho_r@yahoo.com 2009-12-21 10:35:58 --- (In reply to comment #12)
What happens if you set ClientSideWithRender to N (see http://wiki.winehq.org/UsefulRegistryKeys). If that fixes the performance drop then bug 21070 is a duplicate of this one.
Since I couldn't find that registry key, I created it (HKEY_CURRENT_USER > Software > Wine > X11 Driver) and yes, you were right, the problem disappeared when I created under "X11 Driver" a new string value "ClientSideWithRender" and set it to N. Thank you for the quick response.