Yep, I figured it must me as well, strange part though is I'm using the 344.75 WHQL and not the very latest betas which I often do. Typically the WHQLs are pretty stable.

I saw a lot of threads about people getting this effect at boot up, in my case it's just randomly every great once and awhile when I've been playing for a bit.

I think I'll muddle along with what I've got and only change if it becomes chronic. Thanks for the response...