Well, having wired several of these in the past, I am embarrassed to say
that I don't know why my current setup won't work.

I have a 20 amp circuit shared by several switched lights and a couple of
outlets. The load on this circuit is minimal. I recently added a new
outlet to this circuit, just upstream of a switched light. So the circuit
goes to the outlet, then to the light switch.

When I originally added the outlet, I used a standard outlet, and everything
worked great. This past weekend I decided that the outlet should have been
a GFI (damp basement, etc), and pulled the existing outlet and replaced it
with a new 15A GFI. I wired the supply wires to Line, and the
wires-to-the-light-switch to Load. (black wires to gold screws, white wires
to silver). The GFI lit up (the green indcator glowed), and I had juice on
both of the GFI plugs. The GFI test/reset buttons appeared to work
correctly. However, I had no juice going to my light switch. The hot wire
on the GFI Load connector appeared to have juice on my pencil style tester,
but the switch did not turn on the lights.

So I figured I must have messed up the light switch while playing around.
Hard to imagine, but I replaced it anyways, also with a new one. Still no
luck.
I ended up pulling the GFI and putting the original outlet back, and
everything works fine again.

Any clues as to why my "downstream" switch won't work when the GFI is in
place?

BrkrBox ----------- Outlet ------------- Switch ----------- Lights