Well, since you got several computers, why not install them onto the others if they are capable of running the game?
Also, try playing in Windows mode vs Full screen mode?
Actually wait... Does GameGuard initiates when you start PSU online? (the little downloader for patch progressing and etc.)
Also try running the game in administrator mode.
(Right click the icon, run as administrator.)
Maybe your firewall/virus protector?
<font size=-1>[ This Message was edited by: Dj_SkyEpic on 2007-08-15 18:25 ]</font>