I have line 1 and 2 on the VCR/DVD player
Those sound like video inputs, like I described above.
and the TV has video 1 and video 2 (one is for the TV picture and the other for the kids' playstation)
I think you mean that Video 1 is for the input from the VCR/DVD player, right?
and then TV mode which does have a channel but it is always snow.
As well it should be, given the typical satellite hook-up.
Before we got a DVR I had no trouble using the VCR to record live TV, now that the satellite receiver is also a DVR, I can't. Is it possible some DVRs and DVD/VRC combo units are simply not compatible?
A fundamental issue with regard to recording live television using your VCR is that when you're recording live television, you want to use a direct connection from the source to the VCR -- you do not want to try to record live television via connections that go from antenna/cable, through the DVR, into the VCR. DVRs generally do not support "pass-through". In other words, the signal coming
out is what is being
played by the DVR, not what is being
fed into the DVR.
However, with satellite, that's generally not possible with their newer equipment. Most, if not all, of their services are encrypted, so the signal must go through the satellite receiver (DVR). So I think you need to move away from the idea that you're recording live television, and instead you're simply recording whatever is being played by the DVR. That might be the same thing, but there is a fundamental difference: The tuning of what to record happens in the DVR, not the VCR. You shouldn't be trying to tune in specific channels using the tuner in your VCR; you're just trying to tune in
the DVR.
The directv guy did the hook up, not me. But I looked to see how it was set up and the red/yellow/white cables are in use. Once the Vikings game is over and I get the TV back I will take another look. But I have no idea what else to try. Should I try the S cable and the others at the same time or is that overkill?
Having more connections doesn't really get at the root of the problem.

(S-Video can, however, provide better quality video than the yellow composite video cable, but that's a lesser concern to start, right?)