I updated to 2.1 on sunday and haven't listened to MP3s yet (actually pulled sd card when updated). I was using meridian player before the update. I went through and downloaded all my old apps from the market again, but this time there was meridian pioneer. I went to listen to music today and the only thing that pops up is the stuff I've downloaded from amazon directly onto the phone. I started searching the sd card on the computer and there's a folder called lost.dir that is a little over 4 gigs that would be about the amount of music I had on there. All the files in there were renamed with numbers that range from 4 digits to 6 digits. I have all my music on the computer and I'll just put it back on, but I just wanted to make crystal clear that deleting this folder is an alright thing to do, and I'm not going to screw anything else up by deleting the entire folder.