http://bugs.winehq.org/show_bug.cgi?id=9642
--- Comment #6 from Lei Zhang thestig@google.com 2007-09-13 11:11:21 --- The desktop eventually comes back as you interact with it, right?
does running "xrandr -s 0" from the console redraw the screen? does the problem go away if you use a virtual desktop to the run the installer?