I have run into the same strangeness that a few others have spoken about. I have been setting the channel levels with the 990's internal test tones using a Radio Shack SPL meter and setting the volume to 0 for reference and calibrating all channels to 75db. I did have some different levels between the speakers, but I thought that it would not matter as long as they were all putting out the same 75dbs. When I would would play a DVD, CD or SACD the channels did not seem equal (right speaker was louder than the left) and the sub output seemed low. After updating the firmware this past week, I was going to check my levels, but decided to use the Avia test disc to recalibrate. Well, it made a big difference! the left and right speakers are now set at the same channel output level, the level of the sub has been raised and all the speakers seem to be blending with each other and not being independant thinkers! So, has anyone else run it to this oddness, or am I losing it? By the way, the 990 now sounds better than ever and thought it sounded great before!