I'm wondering if something is seriously wrong with the latest batch of drivers. If you have a look here (
http://duc.avid.com/showthread.php?t=366749), you'll see that you are not the only one with issues.
Eventually I had to rollback to pre-Windows 8 drivers (1.0.6?) to prevent regular bluescreens. Now unfortunately, that's not really an option for you, unless you still have a windows 7 license?