Comment 13 for bug 491543

If you look at the problem files in a hex editor, you will see that it isn't a pure FLAC file but rather a FLAC file with an ID3 header.

The libsndfile development version (in Bzr at http://www.mega-nerd.com/Bzr/libsndfile-dev/ ) has already been fixed to read these files. There is no scheduled release date for the next libsndfile version, but it is being worked on.