i've been using a script to convert my flacfiles to ogg

found here: http://www.buberel.org/linux/batch-f...-converter.php

this works for the large majority of my music collection (about 95%) but a few hundred files come up with the error

Code:
ERROR: Input file "/path/to/track/example.flac" is not a supported format
now i've double checked that these files are infact flacs. media players play them as flacs, the mime types say they are flacs and so on.

these flacs were obtained in the same way as the rest of them, by ripping off my CD collection.

anyone any ideas how to fix this or another method of convertion?