Here's the setup (parsed down).
1. RECEIVER (denon 1907) hooked up to a pair of speakers and the two prong power cord plugged into a power bar (NO sources plugged in!).
2. TV (bravia 40" lcd) with nothing plugged into it. The three prong power cord is plugged into same power bar as the receiver.
No buzz at this point.
3. Plug a single cord from the TV audio out to receiver, buzz. Actually, make any electrical contact between the tv and the receiver and there is buzz. (for example. receiver --> coax digital --> dvd player --> composite cables --> tv)
Buzz.
4. Use a 3-prong to 2-prong converter for the tv and the buzz goes away.
Any solutions? This is obviously really annoying. Much thanks to anyone who can help!