Note to people posting messages: please include lots of info so we can more easily offer possible solutions.

Terry, the bottom line might be that you designed and implemented an IR system that worked perfectly with the room the way it was described to you: without a neon sign. That is an undesirable thing to say, but look at McNasty's response!

As for further information, what kind and brand of IR system are you using? Are you using some kind of programmed remote? Do any of your devices have strange IR modulating frequencies? Are there any other funny light sources (I once had IR obliterated by sunlight off the ocean)? Are you using more than one sensor? Could you move the sensor(s) to another location(s)? Is there perhaps an RF version of the IR system you are using (for instance, if you are using a Pronto, the RF version could allow you to do without IR pickups). Did you install shielded wire? Did you install CAT-5? With either approach, are you choosing to put the signals on the different wires for maximum noise rejection? Is your system grounded? Is your IR system grounded to your audio/video system (don't do this with a Niles system)?

And only because it never occurred to me before, have you tried putting largish ferrite beads on the outputs of the IR sensors?

Ernie