[SonicVanguard]

Sounds like a grounding issue (uncommon or messed up ground) or RF interference.

I know it's difficult, but the sub really should be plugged into the same strip as the reciever. That should give them a common ground. But if the florecent light is on the same circuit, you still could be SOL. If that's the case, you'll need some way to isolate either the light, or your audio equipment. The easiest way to do that is some form of power center that can contain or isolate the noisy circuit from your other equipment. Beyond a power center, isolating the circuit can be a bear. We did a rather large audio/video system in a church about three years ago that had the same annoying hum. We found the culprit to be one room the church never had converted from florencent lighting - and it was on the other side of the church from the audio gear. But it still caused us a day of finding the problem and them combating the problem.

Good luck.

Dave.