Media Player was crashing and emptying the playlist on every third song or so, and about at the same point. I put the blame on Media Player and bought tckPlayer. It crashed while scanning for loading its library... I discovered that it was crashing at the same point in each scan, so that if I deleted the oggs that it was loading when it crashed, the crashes would not happen. Oddly, these seem to be the same oggs that made Media Player crash.
What's going on here? I've been ripping with the built-in ripping thing that comes with the KDE desktop/Konqueror (you just go to audiocd:/ and it displays the contents of the CD as MP3s, OGG, etc).
(I just posted about this elsewhere a little while ago... But now know a little more, so another post. )