Tried copying the folder to another location? Or does it just error up again?
And does your user/group have full privilages?
If none of the above work. Get a program called
AnyReader and just copy the file from there to another part of the hard drive (say to the desktop, or to another folder on the ext hdd). You may loose a few songs if that portion of the disk is corrupted, but you'l get the majourity of it back AT LEAST.