I've had my PB2+ for about 3 weeks now. Initially the setup and sound was fine. I've tinkered with the placement of the sub a few times and have calibrated it each time with my receiver's test tones. On one occassion while the test tone was playing the sub shorted out or would "hic-cup" briefly. I've now got the sub positioned where I want it and calibrated it again. During the test tone it again would short out. As the tone is playing the sub will hic-cup several times. I am using a line level cable and put it in both the L and R ports but there is no change - it hic-cup's in both ports. During this calibration the sub suddenly stopped hic-cupping and the tone was smooth. I've played a few movies since and the sub to my ears appears to be playing normally. Tonight I threw in Matrix Revolutions. During the opening scene and I could hear the sub once again hic-cupping. I quickly did a test tone and it is now constantly hic-cupping. I've tried two different subwoofer cables and there is no change. One thing I have noticed however is is if the gain is at a low level it will not hic-cup. Only as I turn the gain up will it start to do it more often. I have had my gain set at about one third when it was working fine. It sounds like the sub is cutting out and I don't know why. When it is working it sounds fine but tonight when I started watching that movie it was constantly cutting out and it makes frequent sounds that I can best describe as being a hic-cup. Any ideas?