I'm sorry to hear of the trouble, but it is not a prevailing problem. When one channel is out, it could be caused by several things: your music source (soundcard or software), speaker wire, satellites, DIN plug, one of a few components in the amp, or preamp.
It sounds like you ruled out a satellite problem. Try using the speakers with another device such as an MP3 player to rule out soundcard or software issues. Another easy thing to check is the round DIN plug in the subwoofer for any bent pins. Be sure to remove it carefully.
If you continue to have trouble, please contact our customer service to inquire about warranty or repair service. 888-554-5665
Thanks!