OK I have confirmed a problem with Outlook 2007 & Vista X64 on AMD Phenom with Visontek Video cards. Now before anyone suggests that it is a heat problem, STOP. Now for those thinking OK how about Video card (Latest drivers installed) or hardware, MAYBE. The toxic combination appears to be Outlook 2007. For some reason it will freeze the system. I have seen similar reports of the same behavior on other threads in the forum.
Here are the symptoms, Boot ICE COLD open Outlook click on inbox, then click on Hotmail (I have that linked in outlook) then system freezes and display Scrambled. Nothing logged in event log. OK so now I reboot, the system comes up fine no problems everything is fine and everything works, uhhhh except outlook. I open Outlook and repeat the steps and BLAM Freeze Then Video Scrambles... reboot everything is fine. Hopefully, someone at Microsoft or AMD will start to look at this. Just sharing my experience...