Any way to repair corrupt m4a (AAC) files?

[bbernardini]

I have my iTunes library on an external drive, and it seems that a whole bunch of the files are corrupt. iTunes won't play them, and I get a "This is not a movie file" error (-2048, I believe) when I try to play them in Quicktime. The files are the correct sizes, and based on what I've read, I suspect the issue is a corrupt header. Is there any way to repair these files without reconverting the already converted audio?

[Pierre.Suave]

1. Open disk utility and

try to repair the disk, see if that helps.

If not, let me know.