I recorded two concerts in PCM on a 1G Hi-MD. Seated shows, with the unit fairly still, not being knocked around. Battery gauge reads full. On playback (also with unit still, sitting right here on my desk), there are two kinds of gaps: one that doesn't return if I rewind and play back the same spot, and one that is apparently a silence in the recording. I tried to transfer via SS 2.3 to see if it was some playback problem in the recorder, and the upload goes along and then just stops, leaving nothing in My Library. (But not preventing the attempt to upload it again, with the same results.) What do the experts thinK? Bad disc? Or problem with the unit? It's an NHF-800, and hasn't acted up before.