If the switch is set to dipole try the bipole setting for the surround calibration and see if the readings change at all.
Make those two changes and re-run MCACC.
BTW what are the crossover settings on the speakers?
I did the calibration in Bi-Pole mode, even though surrounds don't come into play during stereo playback (unless you're DSPing the source) and Aperion states Bi-pole is music play back and Di-pole is best for movies. I'm listening to straight stereo now. The movie listening was very close. Each surround sounded equally good, with the edge going to Aperion. Again, more crisp and clean sounding. This is way I'm asking about the calibration settings. It's the only variable I can think of that is affecting the output.
I'll get the crossover freqs when I get home.
