I discovered that I had this same problem...every single file I had downloaded for the past two years had turned to compressed files that wouldn't open at all. I found a way to get past it, but I'm not sure if it's a temporary fix or what...

Being as I am completely computer-illiterate, this may not be the right way to fix it, or it may be the long, complicated way. Here's what I did...

I uninstalled REALPLAYER from my computer (the program I had been using to play all my mp3's), and then went through and reinstalled it. It really wasn't any big deal, considering I needed an update anyway. Then, what I did was when it asked me if I wanted to use REALPLAYER as my default program for all my mp3's, I clicked "Yes". Then, after I was finished with the re-install, I went back to my windows/shared folder where all my songs were, and they had be changed back to REALPLAYER files. But, they still wouldn't play. So, I went into my limewire progam and redirected my all new incoming downloaded files to a different folder...I just used something random that I never use. Then, I tried to download a song, and when it finished, I went to the new folder and tried to play it, and it worked!

So then I though, why don't I try to put all my songs into that new folder? Maybe it's just the folder that isn't working. So, I put ALL my songs (800+) into this new folder, and they ALL work!!

So, that's what I did to get my files to work again. Whether or not there's a better way or whether or not this will continue to work, I have no idea. LIke I said, I'm completely computer illierate. Anyway, let me know if anyone has any other clue!

Hope this helps you!