For stereo music and 2.1 or 2.2 Dirac recommend pointing the mic to the speakers, that is 90 degrees from vertical, as do Minidsp in all of their Dirac incarnations.
Pps, Arcam provide two calibration files for their mic, one for vertical and one at 90 degrees.
Now I think you're wong here, but it may be me who's wrong!
As I understand it the "normal"calibrsation table is used when the microphone is pointed FORWARD towards the speakers and the 90 degree table should be used when the mic is pointed UPWARDS towards the ceiling.
Does anyone have a definitive answer. Thanks.