Crash on mp3 play-HD410

Hey guys -

I've got a problem that has me scratching my head:

I have a display that is pushbutton activated. Two buttons play separate .mpg files, 4 buttons play video files.

1. After booting correctly, if I choose one of the audio files, they play fine to the end (audioend displays a menu jpg).
2. If I choose a video file first, playback is fine to the end (video end displays a menu jpg.
3. Playback works fine when choosing another button (switches to appropriate file) IF you are going from audio file to audio file, from audio file to video file, or from video to video.
3a. Waiting till the end of a video file, before choosing audio file works fine.
4. Going from a video file in the middle of playback to an audio file causes the screen to freeze and the player locks up. Has to be rebooted.

I have verified the audio is .mp3 (converted from .aiff with Fusion), at44100.HZ @ 16 bit.

I could put the audio stream into a fake movie, but that's more work than I want to do...besides it should work, right?

I program on a Mac, so I don't see hidden files. I've rewritten files to the card several times - should I try reformatting the card and reloading?

Looking forward to the solution!