I had a similar problem a few years back in my 99 Tahoe. Started up, drove five feet into the middle of the road and died. Started fine an hour later. Checked the voltage on the junk WallyMart battery and saw the voltage was a little low, so I broke down and replaced it with an Optima Red Top. Not a single problem since.
If that hadn't worked, it was beginning to make sense to bypass the passlock system. There's a couple companies that sell modules to do this at maybe $40 a pop? that are typically used for remote starter installs.
I think the later year Passlock systems, not positive on the generation number, didn't use the a resistor embedded in the key. It's working the same way as those older systems, but it just checks for resistance in another way. Maybe just with any key? That would make sense if only for the fact that it's just trying to keep people from hotwiring it.