After installing Vista SP1 RC1 and moving Page file to a different hard drive, I was finally not able to get rid of BSODs when computer was idle...
After a coupel of weeks, unfortunately freezes and BSODs came back. The last one I had said something like:
STOP 0x00000050 (0xFFC000000,all zeros,0x964E0FB3, All Zeros)...
Apparently, Microsoft has a hotfix for this. There is an article titled "Error message when you start a Windows Vista-based computer: "STOP: 0x00000050 PAGE_FAULT_IN_NONPAGED_AREA" ( http://support.microsoft.com/kb/939720 )
However, this article mentioned issues during startup, which was not really my case. I kept on looking and found another KB article: http://support.microsoft.com/kb/939720 about STOP: 0x00000050.
From http://support.microsoft.com/kb/244617 I get the feeling that one of the drivers is not playing well with vista. I ran c:\windows\system32\verifier.exe to see if it will be able to help me pinpoint the issue.