I spent this evening calibrating my M2i/VP150 system and discovered a problem. If I calibrate from the center listening position (75db, C weighting, using the Rat Shack analog meter) when I move to the right and left seats of the couch the left and right speakers remain at 75db, but the center channel drops by 2db to 73db. This would suggest that those seated on either end of the couch will be hearing dialog at a lower level than the central listener. I thought the point of the VP150 layout was to eliminate these variations in a horizontally oriented center. Any ideas as to why this is happening? Could my VP150 be defective?