Media Center TV - pauses 3/4 second, plays 3/4 second - continuous loop

Question

SYMPTOMS:

Watching TV on Media Center - the video (not the audio) pauses 3/4 second, plays 3/4 second, pauses 3/4 second - continuous loop. The bottom 5th of the screen is solid green (a rectangle at the bottom extending to both sides).

If I play previously recorded TV in Media Center (from when this wasn't happening), the recording plays perfectly. I recorded a 1/2 hour TV show with Media Center minimized (so it wasn't trying to display it), and I got 1/2 hour of that continuous pausing with the green when I played the recording. I can play DVDs perfectly from Media Center.

If I use Pinnacle's TV software, I can watch TV okay. (But I don't use that - I like Media Center - the program guide, program search, recording options, and the fact the the Windows IR blaster will change the channels on the DirecTV box automatically.)

WHAT CHANGED:

I got a new motherboard and graphics card. (My old motherboard w/onboard graphics fried a second memory chip in 4 months - so it got canned.)
Motherboard: Intel Desktop Board DG41RQ; 2.7Ghz Dual Core Intel; w/2GB ram.
Graphics Card: EVGA GeForce 9500 GT (PCI) (Nvidia GPU w/1GB memory)
There are no yellow ?/!'s in the Device Manager.

I'm still using the Pinnacle PCTV HD PCI - TV tuner card. The DirecTV cable goes to it.
O/S: Windows Media Center (2005) w/Update Rollup 2; Windows XP Home SP3 with all updates.

The Microsoft Windows XP Video Decoder Checkup Utility still reports Cyberlink is the preferred decoder. No new decoders are on the list after installing the graphic card's software.

WHAT I'VE TRIED:

• Uninstalling/reinstalling - Media Center Update Rollup 2, the graphics cards drivers, the Pinnacle drivers, and PowerDVD 8 (the Cyberlink video decoder - I verified it was off the list in the utility before reinstalling it).
• Changing video settings in Windows and on the Nvidia control panel.
• Hours and hours of searching Google.

Answer 1

I solved this problem by using the S-Video output of the DirecTV box (to the Pinnacle TV card) instead of the coax output. This doesn't seem to make sense, as the Pinnacle TV player software worked fine when the coax was used, but Media Center didn't, and Media Center worked fine before with that coax input with the other motherboard w/onboard graphics. So the Pinnacle card's output inside the computer must be different with the coax input - enough different that Media Center fails with the new (and MUCH better) motherboard and graphics card - but not enough different that the Pinnacle TV player also fails. I guess Media Center is more sensitive to part of the signal being screwed up. Picture quality was fine with the coax input (on Pinnacle TV player, and on Media Center with old motherboard w/onboard graphics). Googling for the difference between coax and S-Video, S-Video will give better quality - somewhere between negligible and a lot better. I don't see a difference - but if I had them side to side I might. Anyway, I can watch TV now - so I'm done with this.