We use the id3lib stuff, which I'm sure doesn't search the entire file to try and find ID3v2 tags (at the beginning is bad enough, lots of disk furtling to add a tag - urgh).

I added ID3v1.1/2.0 reading of track number to the low-level libraries, I seem to remember Roger was working on it in emplode (just another column, but with the new sort by... option you can arrange the tracks by track number easily).

Hugo