I run all the CM games on Vista 64. First turn off UAC "User Account Control". Second, install the game in either C:\Program Files(x86), or in there own folder. Don't install them in the "C:\Program Files" directory. Oh and run as Administrator.
If you are having the white out text and slow performance in game, I'm guessing you are running a ATI graphics card, there is a user fix for the text (I can't remember where, but I know it is here), but the poor performance is a ATI driver issue I think.