I have 2 sets of main speakers connected to my Yamaha RX-V3300, one set is for HT/ multi channel use and the other is for stereo use. When I set speakers 'b' to 'main' I get sound thru the 5 surround speakers which would be the 'a' main speakers wether 6 channel input is on or off and both speakers A and B set to off.... sound is bleeding thru, oddly enough I dont get any sound out of the 'b' speakers. Now if I set speakers 'b' to 'zone 2' , and turn off speakers a and b then I get no bleed thru sound with 6 channel input on or off, I have to turn on speakers A to get the sound. What in the heck is going on here? I hope I explained it well enough, if not ask away.