http://bugs.winehq.org/show_bug.cgi?id=18446
--- Comment #4 from Ulrich Keller uhkeller@web.de 2009-05-13 01:37:16 --- It might the display driver. I'm one of those poor Intel graphics re-factoring victims. I have a 945 chipset and currently use the (old) 2.4 driver because of problems with the new one.
In fact I just realized that there are similar problems with other applications too. I see similar screen corruption with Portable Firefox, but it is not persistent: after a split second, everything is back to normal.
However, I get these problems only with Wine. All native applications run without problems.