On Tue, 18 Aug 2009 05:41:53 -0700 (PDT), stan
wrote:

-

That's correct AFIK. Can't have two separate hots in one box.
GFCI outlets compares the current in the neutral and live wires; for
anything plugged into the GFCI itself or any outlets wired downstream
of it. If the current is different the GFCI trips (For safety because
the difference might be leakage through a human).
So you can't use a GFCI for an Edison circuit with it's common
neutral. Plugging into either 'half' of an Edison outlet would
immediately be an unbalance and then 'click'.
That's what GFCI brakers are made for.