[Fizzlemizz]

The textures are stored in the various mpq files so the paths are virtual to the the wow clients extract function (admittedly they most likey are representative of a file structure at Blizzard)

The extract mechanism for mapping the mpq file, the container (blob whatever) of a particular image in that mpq and the "path" to export it to may have an incomplete map(list) of all the textures.

Edit: Extract fails although in-game works is most likely because the two mapping mechanisms were created by two different people/teams