I have a Sunfire Signature sub that I set up in my home theater room connected to a pioneer Elite VSX-52TX that is connected via optical connection to my TV. Day 1, it worked great but now does nothing. I checked connections, etc, even played with Auto and Manual MCACC. It works fine when I check it with MCACC so that tells me connections are good and sub is good, right? It seems like the receiver is working as it sends bass signals when in MCACC ...any ideas?