Even though the manual states that Party Music Mode is a 5.1 matrix of 2-channel stereo, I (and others I have talked to) actually get 7.1 channels of sound. However, today, I suddenly only got 5.1 channels. By rear surrounds had suddenly cut out. Yet when I switch to Club or Concert Modes, they are engaged again. I am wondering if this is a glitch, or if my Halo had somehow got caught in between 2 sound modes? What about you guys? Do you guys get 5.1 or 7.1 when in Party Mode? This was the only all-channel music mode I knew of that didn't use annoying reverb. But now that I seem to have lost my 6th and 7th channels, I am wondering what went wrong?