Re: GT430 + 260.19.21 + VDPAU = artifacts
Actually, it sounds like a lot of these reports are very similar to what I experienced.
However, I can give an update on the framerate speed issues. I believe that this is actually being caused by my TV. The same effect can be seen when watching TV straight from my cable box. I did find a setting on my TV for 120hz stuff, turned it off, and now the framerate is stable (although lower).
I'd also like to add that at the time of seeing these black/white artifacts I was doing a lot of fiddling with settings, killing video player processes, and possibly even starting/stopping X at the time. That is consistent with other reports in this thread and may be a possible cause. Like I said in my original post, a reboot/reinstall seemed to fix it (I had to reinstall the driver because I installed a new kernel as well).