I'm running Windows Media Center on Vista Ultimate SP2. Prior to upgrading to SP2, I could watch TV on WMC through my tuner card (DVICO DVB-T Dual Express), but now WMC doesn't show some channels at all, some show up with jerky video/audio, while others (a minority) are perfect.

I know it's not a problem with the signal, the tuner card, or the tv station, because I can use FusionHDTV and get all of the channels perfectly.

MCDU tells me that I'm using "Microsoft MPEG-2 Video Decoder" and "Microsoft MPEG-1/DD Audio Decoder". I've already done "sfc /scannow" without affecting the problem.

How do I get all channels working again under WMC?