Hey everyone, I already posted about this on the windows 7 thread but nobody responded there so I figured it might be better to make a dedicated thread for it.

I'm running:

AMD Phenom 9750 (long story why - in short it's because I was upgrading from an AM2 cpu which supports some AM2+ cpus)
4 gigs 800Mhz DDR2
Hauppauge 2200 (using the drivers on the disk, as windows update wouldn't recognise the device or find drivers by itself)
Sapphire Ati hd4870 (have tried the drivers w7 installs by default and the w7 beta drivers offered by AMD) outputting both audio and video through the hdmi dongle.
Philips 47" 1080 lcd
Windows 7 beta 7000

I'm honestly not sure if this problem is a windows 7 thing or something to do with my ati video card... maybe someone could direct me to the right place?

The only channels I can tune into are 1, 2, 3 and the HD preview channel. Any other channels have munted-looking green and black squares for their video most of the time. Even the channels that work go all jittery every so often (it seems to get stuck on a couple of frames, repeating those over and over ad infinitum), although the jitter is fixable by minimising then maximising Media Center.

I haven't really tried using h.264 much before. When I first got my tuner card I tried using media portal but due to constant timeshifting errors and other problems I gave up on it and switched to vista media center analogue. Since installing windows 7 I've been trying to get hdtv working.

Looking at old threads suggests that there are issues with ati graphics cards and h.264 acceleration. Is this likely? The old threads I could find didn't seem to mention the hd 4000 range as they were 6 months old. Do the hd 4850s and 4870s still have this issue? According to those threads it suggests that turning down hardware acceleration might help. How do I turn off hardware acceleration in media center? I'm imagining that I might not absolutely need acceleration, as my cpu is pretty decent and supposedly windows 7 is better optimised to make use of quad cores. Either way, it would definately be worth giving it a try!

Any other ideas as to what could be the problem?

Cheers,
Patrick