I am currently waiting for my replacement video card, and hope that will fix things.
Still, a few question remain tha ti am hoping might help point a finger at a culprit:
1. I did notice that the most reliable freezes I had were:
A. 10-30 minutes into capturing video from a firewire camcorder
B. ~10 minutes into having Picasa scanning pictures for faces.
While waiting for video card, I am also using the windows "Verifier" tool to look for driver
resource deadlocks. doing this in parts, but I should be done tonight. So far, freezes have not been noticed by Verifier.exe.
Thank you for any advice and guidance!