I got a refurb Fuze v2 for my mom and put all the music on a SanDisk 8GB class 2 microSDHC card to leave the internal memory for recording. At first it worked, then the OF stopped booting whenever the card was inserted (no changes to the unit between when it worked and when it stopped).
I tried that card on my own Rockboxed Sansa e200 v1 and it worked fine, so it doesn't seem to be that the card went bad. So I figured, might as well install the unstable but nearly-finished Fuze v2 Rockbox and see if that helped.
I installed the June 24th, 2010 version. I got (different) error messages when booting to Rockbox with the card inserted or inserting it after Rockbox boot. Sorry I can't remember which was which, but one message was:
*PANIC*
microSD init failed : -3
(white text on black background)
and the other was:
*PANIC*
card not initialised (-3)
(black text on white background)
I just updated Rockbox to today's version (July 2nd), and it now gives the second error when both booting with or post-inserting the card. I also tried a Polaroid (branded PNY) 16GB class 2 microSDHC card with the same results.
Not sure if there's any other helpful info I need to give... Any suggestions for me, or is this just basically a bug report?