I have been experiencing an issue since I've up upgraded to Windows 7 where all flash videos have horrible frame rates when run in full screen mode. I have tried multiple browsers and i have the latest version of flash and video drivers. I have tried re-installing flash and disabling hardware acceleration. The problem occurs on youtube and hulu.
This is a clean install on a Core 2 duo with 4GB RAM and an Nvidia 8400M GS.
Best Answer
Okay, I think I've got this figured out. I thought it might have had something to do with Aero being on because it started working fine when I disabled it. However, I have been able to reproduce it by messing with the hardware acceleration feature.
I think the fix is indeed to disable hardware acceleration. I didn't see any change at first, but when I reloaded the page (F5, or CTRL+F5 for full reload) it started working.
The fix: