My suspicion would be that your room is less "live" than what the designers choose as "typical". I don't think this is a bad thing as the general consensus is that a less reverberant space allows for a more convincing multi-channel effects recreation.

Is this sort of initial mis-sizing consistent if you try elevating the mic above your true listening position? Maybe the upholstered furniture and such is throwing off the system.

The 990 manual explains how to manually override the auto-setup. http://pdf.outlawaudio.com/outlaw/docs/990manual.pdf