Nice
front projection setup, twopecker!
Hmm... I don't see anything overtly wrong in the picture and your descriptions, except that the L/R mains appear to be fairly close to each other. Given that you are 10' away from the fronts, the ideal distance between the L/R would be 8'~10'. And if you can, try moving the M22's further forward, so that the L/C/R are all equidistance from you (and accordingly change the delay settings on the receiver). These maneuvers may further improve the front soundstage and dialog clarity.
Coming back to the volume level issue, when you say you calibrated the system to 75dB at the listening position, what level did you set the master volume knob? (I ask this because the 41TX doesn't seem to automatically reset it at 0dB.)
JohnK's suggestion of temporarily swapping the VP150 and one of the M22's to see if it improves the dialog clarity is a good idea, too. In fact, since you use front projection, you can get another M22/stand as the center channel (move the electronics rack somewhere else in that case).
