I recently had to reformat my SD card because it became corrupt (see my previous post). After losing ALL my nandroids , I decided the issue could have been due to me converting .wmv music files to .mp3's. I know it's lengthy but, please read. It might save you a lot of time and trouble. Thanks! I was on CM7 and, apparently, .wmv files aren't supported - I tried 2 other AOSP roms (Destoyer & MIUI) and sure enough I still couldn't play any .wmv music files. This struck me as odd since all of my Sense-based roms always played these files, I headed over to the forums and the concensus was that I would have to convert the files. I dl'ed a free converter, and a couple of hours later, I had all my music as .mp3's and they all worked on CM7. The following Saturday night, I went to a friends house and we plugged in my phone, via the headjack, to his surround sound system. It was already late and eventually my phone died. The next morning I plugged my phone, for it to charge up, and about 2 hours later had to leave to run some errands; I didn't notice it at first but the SD card icon had come on in the upper lefthand corner. Once I realized it was there, I pulled down the notifications and it basically said that I would have to reformat the SD card. Trying not to freak out, I rebooted into recovery to restore a backup, the only problem was that I didn't have any nandroid backups! I went into Astro file manager and it wouldn't read my SD card and, since the backups were on the card and my card was now "corrupt," it wasn't reading anything on it. Trying to stay cool, later on I decided to pull the SD card, nothing. I then decided to connect my phone via USB, nothing. I then inserted the card into my PC, nothing. And, just to make sure, I inserted the card into my laptop, nothing. It was now obvious that I had to reformat. Eventually I did and, thank God, I'm now back up and running like normal. . So I decided yesterday to run an experiment. I have an extra 2 gb SD card and I packed it with converted .wmv files and placed it in my phone. I played every single file and eventually let the battery run out. And guess what? THE SAME EXACT THING HAPPENED! When I recharged the battery - for about 45 minutes - I got the same message and the same SD icon as I had gotten before, BTW, I was still on CM7. I reformatted the card, flashed Myn's Warm 2.2 charged the battery to 100%, and proceeded to play the exact .mp3's as before. This morning I woke up and sure enough my phone died - I placed the volume on it's lowest settings and with headphones on while I slept - I charged the phone while I went to the gym (about an hour) and, when I came back, I checked to see if I had the same SD corrupt notification. I had nothing! The phone was okay. No notification, no icon and all of the music worked fine, I was even able to go into Astro and see my SD card contents. My conclusion: the free converter software must be corrupting my data with CM7 and, perhaps, other AOSP-based roms. I'm almost certain of that. I won't mention which converter software I used but let's just say it was one of the top hits when I searched on Google. As of this post, I am now attempting to replicate the same results using Destroyer and using the same exact converted music files as before. I will update you guys by later on. Thanks for reading and I hope this was somewhat useful.