I'm using Rockbox since 2006 on my Apple iPod mini and there haven't been any real issues for me until now. I love Rockbox and can deal with most problems but this one is actually a showstopper:
Once in a while my iPod won't boot. I'll just display the battery low warning and then shut down. There's no way to enter Rockbox or force it into disc mode. Trying to recharge won't help either: It'll just show the first frame of the charging animation forever (I tried "charging" it for 48h and it didn't help).
The only solution that works for me is to remove the battery from the PCB and reattach it after a few seconds.
Rockbox will lose the current time but it'll boot again (Apple logo, Backlight, Rockbox splash, Main menu)
I'm currently using a daily build (r16316-080215) on an iPod mini (hw rev: 0x00070002; 2nd gen, 4GB, Silver) with the ipodmini2g bootloader from March 2007.
It seems to be a rare problem (forum search didn't turn up anything) and I haven't figured out how to reproduce it.
Thanks for reading/replying in advance.