http://bugs.winehq.org/show_bug.cgi?id=20736
--- Comment #1 from Henri Verbeet hverbeet@gmail.com 2009-11-17 04:29:38 --- This is related to the ImageAddCertificate() fixme. Hacking it to pretend it succeeded should allow the game to complete installation, but is not correct of course. The demo and a few other games actually suffer from this as well, afaik this was introduced by the last Steam update.