KrisSBoyd
One of the things that I find that trips up IR and their receivers is halogen lighting, plasma TV's, and sunshine, among other IR noise generators. It's very possible the receivers are being "blinded" partially by one of these. Kind of like trying to hear some one on a phone in a noisy room. Gets hard to pick out the good from the bad. It's the same thing that makes learning codes on the Pronto's a pain sometimes. They can be very sensitive to any stray light. If the room is dark, and you give it an ON command, and it works, but gets touchy after the lights are on, then you're on the right track. Regular soft light bulbs usually are okay. It's the halogens that generate noise. It's why Xantech, Niles, Speakercraft and others have CFL or Plasma friendly versions of their IR receivers. Lately, since the newer RF6500 extender has come out, I use it all the time, now, to get around the problems of repeating IR.

If it works in the dark room, start turning off things or blocking stray light from the receivers until it works and you find the culprit.
Good luck!
Dan