Pytanie CPU Physics different each run.

I'm having a problem with the CPU Physics test where each pass the building seems to collapse in a very wide range of ways. It either just sitting still almost where only small amount of broken wall falls off giving me a very solid frame rate (80+). Or the entire building seems to completely fall apart giving me system crushing frame rate (<10). This causes my overall score to go from 12k at best down to 9-10k without changing anything with the system or settings.

I'm Running 2500K @ 4.6 and SLI GTX460s.

Just realized i hadn't installed Win7 SP1 since my format this weekend. I'll re-test once it's installed and see if that fixes the issue.