I've got an SL-5500, with OZ and such. Lately, I haven't been able to read my SD cards. I have had a 256 PNY for a while, and once I put some mp3's on it through some proprietary software, I'm pretty sure it hasnt been working. I tried to reformat it using Windows into FAT16, but my Z still wouldn't read it. I tried to see if my friend's ext2 formatted card would work, and it didn't. I also bought one from the store, and it doesnt work. dmesg says that a device change was detected, but doesnt do anything about it. I can try to post the entire dmesg if neccessary.
Any suggestions?