I think it's because I had uploaded it on 4shared previously (the full 38mb WAV version), then I erased it off because of it's size and put it the compressed version onto rapidshare, then I uploaded the same name again back to 4shared because people were having problems with Rapidshare.
I have renamed the file to Craig 5 and it now works fine. It seems that once a file name has gone onto 4shared you can't use that name again.

[This message has been edited by Craig_UK (edited 09-14-2006).]