First the timecode changed from elapsed/total to only showing elapsed, and my VolAdjust setting changed from Med to Off. I only noticed it because I found myself changing the volume between songs and realized I shouldn't have to do that. Another time it switched to a previous playlist.

You are describing a loss of the user settings in the player's Flash RAM. You would probably also note that the Loudness and Dimmer settings are hosed, as well.

I have had this happen on my Mk2 player twice. It has been discussed among the alpha team. It is not certain if it is a player bug, or if it is due to a something in Mark's kernel that I was running at the time-- Mark said there was something which might have caused it but he wasn't sure. The latest build of the kernel has corrected the thing he suspected, but since the flash-loss was very rare and intermittent for me, I have no idea if it corrected it or not.