Thank you very much for the suggestion Disrupt. I put the patch on my Clip Zip from the link you specified, but the problem unfortunately, persists.
Since you also asked if version 3.13 has the same problem, I downgraded to 3.13, and I see the same problem on that version as well. I guess that rules out low-voltage as the culprit.
I've been trying to find a pattern with the freezing. My current test works like this:
I have shuffle off. I play a song from the file browser directly, no playlist or database.
When the song begins, I reboot to clear the existing memory.
When Rockbox comes back up, I wait for the song to being playing.
I wait one second, then press "next" to begin the next song.
I let that song play for one second and press "next" again.
Eventually, Rockbox freezes.
When this happens, I reboot to return functionality, go back to the original song, and start it.
I then reboot to clear memory, and follow the steps from above.
Strangely, Rockbox freezes at a different song each time. Sometimes it's the fourth song, sometimes the 40th.
If some of my files were corrupt, or my micro SD card was damaged, I would expect Rockbox to freeze at the same song each time. Also, if my tracks were somehow chewing up too much memory for the OS to function, it seems like the error should happen roughly around the same number of tracks in each time.
Does Rockbox have a debug log I can turn on?
And, can anyone think of anything else that I might try?