Hi Dave, so far yours is the only report of this behavior so I don't have any pattern to work off of.

My best guess is that you possibly had switched the driver that you were using, and that's what actually changed between using the Oct beta and the new one...

One other tip - try going to the nVidia control panel and disable the option for "Threaded optimization", sometimes that will solve some problems like this with nVidia cards.

- Michael