Ok, I have looked around and seen SOME topics on this, but no real resolutions (if they did start working again, it was due to mysterious luck).
I have the latest build of 7, am using a tuner card that came with my Dell XPS430, and am using it with a DirecTV set-top box. Also, the remote and IR sensor came with the computer too, but I got the IR Controller (blaster) and extension cable online.
Here's the situation as of now: I had it working WONDERFULLY last night; changed channels quickly, set up recordings and recorded on-the-spot, fully-stocked guide, etc.. but this morning when I went to mess around with it, it could do all of that except change the channels on the set-top box! Literally same setup, no changes from last night, and all of the connections are still good (the IR blaster did not fall off or change positions at all). I tried re-configuring the entire tuner setup a few different times, going through getting the remote control setting down different ways (with the actual remote to the IR sensor at the PC).
Any other things I could try? I even went as far as to make sure the box was just watching live TV, no DVR recording or rewound TV, just sitting there.
Side Note: Of course, for some reason, the PC doesn't recognize the "local" channels with the satellite (0-70) as in, they aren't even in the guide, and when I woke up this morning my girlfriend had left the box on one of those channels (using the box itself, not the PC of course), so when I turned on the computer, IT thought it was on animal planet or something, but the signal was the local news channel.
I know it's a lot, but I tried to break up the paragraphs so that important stuff is easier to read.