We have a Sony RDR-HX950 DVD/HDD Upscaling player and also a little Sony portable DVD Player. Both of these are hooked upto a Denon AVF 589 - the upscaling player through coax and the portable through optical.

The Upscaling player is pretty picky about what DVDs it plays - about half of the discs from fatso it refuses to play due to scratches etc.

Tonight we were watching Pineapple Express from fatsowhich is pretty new and the disc looked fine to me. But at several points (about five or so) throughout the playback the sound dipped out for a second or so. It was repeatable at the same spot.

Putting the disc into the portable player and I could not get the sound dropout at those spots.

Any idea what could cause this sort of thing?