|Okay, I probably shouldn't, but I now I'm curious as to what's eating the CPU.|
Step 1) Download and run Process Explorer
Step 2) Open the Properties dialog for "System"
Step 3) On the Threads tab, sort by CPU. That should tell you what driver is eating all your cycles.
Step 4) Report back! I want to know, it's polite, and you're liable to be ignored in the future if you don't.