I'm trying to replace the outlet next to the sink in my bedroom with a GFCI outlet. Everything is wired correctly but it trips instantly when power is applied and it won't reset. I've tried two different units, same results. Until I can figure this out I've installed the original outlet and it works fine. This outlet also provides power to the bathroom light and vent fan. I have installed these before with no problem so this "5 minute" job is frustrating me. Could the house wiring be incorrect and still work OK with the regular outlet but not with the GFCI? Any help would be appreciated.