TV/Video lousy on HDTV?

[Pinger]

When watching online programing such as Hulu Tv through Windows 7 picture quality isn't very good(jumpy and stuttering) but when I boot into my Vista OS the quality is much better and doesn't jump or stutter. I found nVidia has new Windows 7 drivers for my GeForce 7800 and loaded them today but it didn't help at all.. Anyone encounter this and find a fix?

Dell E520 Pent. 4 3.06 Ghz w/2gb ram
GeForce 7800 with dual dvi outputs.
ISP source is Comcast Cable.
Windows 7 build 7100
Vista SP2
TV-Samsung LN-46A850 set to "just scan"

 

[Pinger]

I should have mentioned I'm talking about watching these shows on our 46" Samsung LN-A850 LCD which is connected to our Computer running Win7 via DVI/HDMI.

 

[Snufffed]

The new drivers? are they signed? Are they Beta?
1. try installing an running in Vista SP2 mode.
2. Delete the new drivers, reboot and check to see if the Win7 default installed drivers do the same...