So, I'm starting to troubleshoot this issue. I bypassed the receiver and plugged an audio source directly into my HTD 1240 amp. BINGO! My low volume issue seems to have been fixed. Originally I had analog sources running through my Denon 2313's second zone, but I was getting weak volume from my 6 ceiling speakers. Now, my question is: Why would running through the receiver limit my volume? And, why would zone 2 overheat if I was using the preouts?