Sometimes, not always, although the auto-numbering works ok, the format is not homogeneous for all the track numbers, when we mark the option of 'Insert Zero before track number (I am using spanish version and I am not sure how the option is named in the english version).
But if I am waitnig for track numbers like 001 002 003 004 and so on, what I can see is something like 001 2 3 004 005 and so on. The Zero's before the track numbers desappears. If I auto-number again with the same song collection, the same figures appears. With another collection of songs, the Zero's are missing in another songs.