Yes, that model number sounds right. You are probably correct about the speaker hookups. It only started happening after I unplugged and rehooked up some things (when I added the sub) to try and get better sound.

I connect my DVD to these 6 inputs. This receiver doesn't even have an optical connection. Do you think I should upgrade this receiver?

I will try to re-hookup the speakers (cleaner). What is (or advantages) of "Crossover"?

Thanks for your reply!