Merlock, hopefully one of the more technical folks will check in to provide some direction. The only other thing that comes to mind is from a recent thread I saw with a similar problem.
Take a very close look at how you have connected your speakers (i.e., the wires connected at the speakers and at the receiver). You may have a bare wire touching something it shouldn't and causing a short. Start the process by disconnecting one speaker at a time (at the receiver connection) to see if the problem goes away when that speaker is disconnected. If so, then there is likely a problem with the connections involving that speaker.
The connections may look OK, but a short can be well hidden and can cause havoc.
I hope this works for you. I'm pretty much out of spit. Well, almost - I DO know a shaman who can cook up a few herbs and chant for a couple of minutes, but that solution choice might be suspect.
