[masraum]

I would say that for any circuit (with or w/o GFCI) it's possible for one or more points on the circuit to work and then one or more other parts downstream to not work. Although that would, I would think, almost have to be caused by wiring issues.

I suppose it's possible that there could be an issue with the GFCI mechanism that could cause a lack of juice downstream, but I don't know for sure. I assume they are pretty basic, and if the two buttons appear to work normally, then I would expect the power to work through it as expected.

What seems most likely is a bad/loose connection somewhere or another GFCI somewhere that you're not aware of.