This only started happening in the past two days, which seems very odd to me. Everything worked flawlessly up until now, and I use my my computer as my primary TV.

Flash video from Hulu and Amazon, for no apparent reason, now have lots of artifacts in them. Some scenes are ok, but some are completely scrambled and unwatchable.

• My connection is a 15mb fios, and bandwidth tests indicate my connection speed is ok.
• I've tried the latest production version of Flash, as well as the 10.1RC4. Same problem.
• Enabling or disabling hardware acceleration in Flash makes no difference (with the scrambling issue, quality is better overall with hardware).
• Using a different H264 codec doesn't clean up the issue, although the scrambling does look different.

I'm kind of stumped. The only thing I can think of now is to reinstall windows, which is obviously a drastic step.

Edit:

Forgot to say:

Windows 7, Athlon 64X2, Geforce GTS 250