grainy/snowy video

For Christmas I received a new capture card. It's the Hauppauge WinTV-HVR-1800. So far it seems to be a pretty good card. I'm just having one problem though. I've watched shows with it in Media Center, BeyondTV and VLC, but they all seem to be a little grainy/snowy. I have the cable straight from the wall to the card, so it's not going thru any other sources or connectors. Any ideas what may be causing the picture to be grainy/snowy? I've included a pic below to show how the video looks. Thanks for any help anyone can give. :)

http://img174.imageshack.us/img174/6...9932ja3.th.png

If it's analog terrestrial/cable tv then it might be dozen things starting from poor singnal, power lines around the signal cable, poor quality of cable.

Analog TV Tuner cards have much higher sensitivity compared to normal TVs.
You can try connecting the card through VCR (with build in tv tuner), coaxial cable to VCR then S-Video/SVHS cable to tuner card.

Digital signal is way less sensitive to above behaviors and it delivers way better quality and sharpness.