I own an HK AVR-320 and finally hooked up an external amp to test my surround back channels. When playing 2 channel sources thru Logic 7, DTS Neo 6 or 7 channel stereo I can get sound from all 7 speakers. But when switching to Dolby Prologic II I only get output thru 5 speakers. In fact when I went into the setup menu, I wasn't allowed to enable the surround back speakers in DPL II. I'm wondering if this is just an HK issue or perhaps DPL II only works up to 5.1 and not 6.1 or 7.1? Is it different on the HK 325/525 since they have built in amps for all 7 channels?