I am finally digging deeper into my DM4800 as I put together a mobile recording setup. Tonight I was finally bussing things into groups and when I was trying to pan a drum mix across two channels summed into a stereo pair it would only come out mono. No panning. Am I doing something wrong? In this particular example I have a drum mix with kick, snare, and one overhead with two close mic'd toms. I had each source routed to a pair of busses linked into stereo. I wanted to pan the toms a little left and right and try as I might it remained mono. It wasn't until I just selected the left bus of the pair for one and the right bus for the other that I was able to get a stereo effect although it was 100% panning. What's up with this?