i just installed a Hauppauge 2250 and am using Windows 7.

The problem is that i receive my analog cable channels fine thru 38. Then 39 is very grainy and black and white. I don't get any reception on channels above 39. All digital channels seem to work fine regardless of channel number. I received all analog channels fine when this same cable was plugged into a TV.

Anyone seen anything like this before or have any ideas?

i just discovered that i also have channels above 60 available. So there is this band of channels from 39-60 that don't work! i can't figure out what this means. comcast customer support was of course completely unhelpful (they think i need some sort of box).

If they worked on a TV, they should be available to the PC's tuner.

1) did you add any splitters, new coax cables, etc.?
2) have you tried rescans or manually adding missing channels?
3) have you verified that there are no firmware updates or issues with the 2250 and Win7?
4) What program do you use to view PCTV? Have you tried other viewer programs?

Are you sure ComCast hasn't recently de-commissioned them to reclaim the bandwidth for digital? Here in Olympia that's the case, everything above CH. 29 is now being used for digital.