Member Casestream posted this below, but apparently the problem went away on its own, so there weren't any responses from the Rescue Squad. Here's the original post: I'm having literally the EXACT same problem right now, down to the letter. Working last night, fell asleep listening to music off the SD card, woke up this morning with the music still playing (so no damage yet, obviously, because it was still working), all my core temps were normal according to SetCPU. I never even restarted the phone, I just unplugged it and put it in my pocket like I always do and then an hour later when I tried to launch something, I got the dreaded "Bad SD Card - Reformat?" message in the notification bar. I don't have a card reader except on my PS3, but the PS3 couldn't read it either. I can't get the card to mount on any of my computers and Astro says the card is blank. WTF is going on? Did you ever figure anything out? I NEED THIS STUFF! 16 GB of unrecoverable music and two years worth of pictures would be a huge loss, not to mention the incredible pain in the ass of reformatting and redoing everything. Just when I got MIUI running all smoothly, too. Crud. Any help would be appreciated.