http://bugs.winehq.org/show_bug.cgi?id=11506
--- Comment #4 from Roderick Colenbrander thunderbird2k@gmx.net 2008-02-08 03:57:08 --- The menu covering bug is 'normal' right now. I have been working on a fix for a while but it is a very complicated patch. Big changes in wine's x11 driver are needed and this way it affects all apps running on Wine. That bug is 9917.
The fix for the 'black window' won't fix performance though.