Almost sounds like the original manual switch turned the outlet on and off.
Now using a XPS3 to control the outlet, but this is speculation till more details are available.
That way if I am incorrect I look like an idiot.
Sorry for not replying sooner. I need to check my options on this board as I didn't get any emails that there were responses. Anyway, yes Brian you are correct. I have a switch inside my house that controls the outdoor outlet. Three years ago I replaced the normal rocker switch with an XPS3 and it worked great. The GFCI outlet seemed to crap the bed so I replaced it with a brand new one. Now I'm having the problem described in this thread. Like I said, I removed the XPS3 and put the original rocker switch back in and the GFCI works just fine. I put the XPS3 back in, it turns on (red light) but trips the GFCI. I can't reset it.
I can try just switching the breaker to a GFCI I suppose but they are expensive I think. But this is a headache so I may just go that route.
Thanks for the ideas. Any others besides change the breaker to a GFCI?
Edit: I should also add that if I take out the GFCI outlet and leave the XPS3, everything works just fine again. It appears that the combo that doesn't work is the GFCI outlet and the XPS3 together. I may run out and get the GFI breaker and give that shot.