I was recording on my iRiver today and when I looked at the screen a couple of hours later, there was a fatal error message- something along the lines of can't write to the disk.
Put the card in a card reader, and couldn't access it (XP). Plugged into Ubuntu I could access the files and copy them off. Nuked the partition in Gparted, formatted it to FAT32, put the Rockbox folder back. Can read/write to it in Ubuntu, but XP dones't want to know - unrecognized device error. The iRiver also denies its existence. It shows up as a removable drive in Vista, but I can't access it - please insert disk into drive x error.
Time to replace this card? Seems strange that Ubuntu has no problems accessing it