Stubborn tracks playing out of order when shuffling albums. Changed sorting tags, wiped ID3 tags, nothing works.

Certain mp3 tracks I've added to iTunes will play out of order when I've got my iPod set to shuffle albums. So for instance track 8 will play as track 1. Usually I can overcome this by going to the Sorting page and making sure everything is the same for all the tracks of the album. But there are certain ones I can't get to behave, no matter what I do. I've tried changing all the sorting tags to something else and back again, I've even tried third party software to wipe the ID3 tags, still the issue persists.

It doesn't do this in iTunes, only on my iPod.

Any help much appreciated.