alt+tabbing will fix the blank screen, but it doesn't fix the 100% CPU usage with dual core, which is the cause for the stuttering. the game just wasn't programmed properly, as i've tried much older games that have no problem with the dual core. obviously, something in the way they coded it was done in such a way as to cause problems, and most likely, it cannot be fixed.
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Actually it is a NVIDIA driver issue. Check the NV forums. This issue is caused by the release 80 Drivers with the Dual Core Optimizations in them. I am using the latest 81.89 and the problem is stil there. If you go back to release 70 drivers the issue disappears.
We need NVIIDA to fix this.