A few months ago, this happened to me, first time my SD card was reading "SD card blank or has unspported file system", which all my music files and pictures were wiped out or so it appeared. Transferred the SD card to another reader, was not able to read it or format at all, so total loss. Not only that my droid was automatically turning back on when I had conveniently turned it off. this haooened quite random. So I called the Droid support system, the agent indicated that they have not heard of such reports that this is happening...however, they agreed to replace my SD card, so they sent the necessary information. But what bothered me was in order for me to get a replacement SD card, I had to ship it overnight express, so not to damage it...and get this, I had to pay for overnight shipping. at the cost to ship a chip overnight was costing ~$, so I figured what sense did it make to pay that cost to ship that card when I could just go out and buy another one for the same cost. So I did, went out and bought one...my loss.
Months later, (actually yesterday to be exact), 2nd time, happened AGAIN..."SD card blank or has unsupported file system...not able to format, everything wiped out AGAIN, good thing I backed things up on my computer, so now I'm out of another SD card, called the droid/motorola community, once again, they say they have not heard of such thing happening, or maybe I got the wrong agent again. They were willing to have me ship the phone to them, for any type of repair or take it to a location. I am going to Verizon.
I just refuse to believe that they are saying they have never heard of the phone turning back on, when manually turned off and the SD cards being wiped out like that. Makes no sense to me at all.