I ran into a problem with a "plasma proof" IR target by Speakercraft when I got all kinds of signal without the Plasma being on. First I checked the my laptop, it was not on, next any other devices.
I found a motion sensor in the same room and covered it and suddenly the noise stopped. Could this be the cause of the equipment only responding some time? Anyone else run into this problem and if so how do I fix it. The response is ok for now but I fear we may have problems later.

The motion sensor is most likely your problem. They are commonly called PIR's (passive infrared) and shoot IR rays out that must be crossed to trigger the alarm.
The pattern is adjustable, but may compromise the security coverage in that room.

Since the IR is sent out in a horizontal "finger" pattern rather than a full "blast", you might try moving the IR reciever to the left or right to hopefully find a dead spot.

This message was edited by pilgram on 01/11/05 00:00 ET.

One alternative that worked for me was to pop the lens on the PIR and put a strip of white tape vertically on the inside of the lens. It knocked the IR output down enough to make it work.

Your diagnosis is correct, but the passive ones don't shoot out IR. They are passive and sense when IR crosses the sensitivity paths of their sensors. IR as given off by body heat. Or remote controls perhaps; can a remote control trigger such an alarm?

I have not run into a problem of a remote triggering a motion sensor, but I have had a dimmable halogen lamp cause the volume contol on a receiver to rise without stopping. Thanks for all the tips. I am gonna try some of that stuff you guys suggested.