This is a little off the topic, but I had a problem with this kind of thing with my onkyo home stereo. When I would be in the dolbypro logic mode with the add on onkyo eq on I would get all kinds of distortion just like what your describing with the rio. When I would have the eq off it was fine or if I turned the dsp off and leave the eq on it was fine, the eq settings were all almost a flat line too with the mids and bass down a little. I tried a technics eq with the same settings and the problem went away. It was very strange when there would be a loud boom in a movie or music the bass would sound like it was cracking.

p.s. Tony... could you send a copy of beta 12 this way