I had the same problem with my 530. I changed coax, switched outputs and coax from the multiswitch to the other 530, and still the problem persisted. I had even recorded the same event on each 530 and only one would have sound dropouts. The last week I have also noticed jump ahead or back would cause the unit to freeze for a moment. Starchoice had done a few MR with and without harddrive erase, this would solve the problem for a few days. The unit seemed to work better with BC (maybe this is a cause of the problems I now have) but then it would sometimes drop recordings. Starchoice is now sending me a replacement.