http://bugs.winehq.org/show_bug.cgi?id=25432
--- Comment #4 from Dan Kegel dank@kegel.com 2010-12-06 13:26:48 CST --- That's what Alexandre implied.
I've heard an alternate workaround is to set nt4 mode, but you have to do it with winecfg, the verb in winetricks is insufficient. We should have a fix for how winetricks sets windows versions soon.