I forgot to mention that I've had freezes during browser use as well. It happens in exactly the same way as you described earlier in the thread, except I use Firefox.
For me the browser freezes became a lot less frequent since 10.6.7/latest nvidia drivers/Firefox 4. Can't say which because I updated all three at pretty much the same time, but the freeze is rare enough now that I've stopped running VLC in the background.
I was using Left 4 Dead 2 for testing your BIOS because it is a much more reliable way to make it freeze. I can use Firefox all day and night without anything happening, so I decided that it would take too long to get a reliable test result that way.
FWIW, that unlimited love qt video runs fine for me in Firefox on 10.6.7 already.
for me exactly the same. just another game