I have an Onkyo TX-SR500. About once or twice when playing DVDs through it, the sound will cut of for a split second, just long enough to glance and see that where it usually displays "D Digital" or "DTS" is blank, then pop back up and remume normally. It does not do this for other audio sources. I have the DVD player hooked up with a digital coax, and this only statred recently. I was thinking about getting an optical cable to see if it was a signal problem, but I've had this setup for a while with no problems. Any suggestions? Thanks.