Just got a new Denon 1804 and made the major change over of cables from my previous Denon 3200. I was even able to do a test tone and hear all five speakers (and sub) sound off. After playing around with it for awhile though I've encountered a repeating problem that's driving me nuts now. When the reciever is in stereo mode - no problem. As soon as I switch to Dolby Digital or Dolby Pro Logic II (i.e. a surround sound format) the receiver shuts off completely and the "standy" light blinks. This strikes me as odd because at one point I was demo-ing "Hulk" to test the sound. It seemed fine then. And, as I mentioned, I was able to do a successful test tone to make sure the speakers were all hooked up. I'm sure the source is a surround sound one too on some satellite channels I tried. My first thought is that I crisscrossed my positive/negative rear speaker cables so I changed them and reconnected into the receiver (several combinations). It still shut off. I had previously hooked up the Zone 2 rear surround speaker (a third center rear) so I finally disconnected that to isloate the rear channel problem. Anyway, regardless of my troubleshotting on this, the receiver still shuts itself off as soon as a surround sound format is selected and begins to kick in. Can someone help me out with some advice on this? Everything else works fine (video cable inputs and standard 2-channel stereo audio). My front speakers, center, and sub are sounding fine, too. Much appreciated!