My guess, and I think Al will chime in here with more knowledge than me, is you have two legs feeding the old plug. I think they have a connector you can remove that jumps juice to the other plug. That way you can have constant current on one plug and switch the other. They probably thought they could up the capacity by doing the red on a different breaker. GFCI probably don't have that removalble jumper so what you have is a dead short wired the way you have it. And like has been said, I bet taping up the red will make it work. Al????