Problem Recognizing Folder

[Adol]

After mounting my Neuros II in Linux, I found that the directory I saved my music files to has changed to an "unknown file type."  The remaining space on the player doesn't appear to have changed, but I can't navigate to the music files at the moment.  

My best guess is that I need to somehow modify this "unknown file" in a way that lets browsers or database managers to view it as a folder, but I'm a little uncertain as to how to go about doing that.  I'd assume that there must be some sort of header I'll need to modify.

I'd guess that my music files are unharmed, but are in a sort of limbo since the path to them is screwed up.  Has anyone else had this problem, or does anyone have any ideas on how to solve it?

Thanks in advance.

Edit:  It turns out that my filesystem was corrupted, and was fixed easily using fsck.