Mp3 tags problem

[Nigel Ridley]

Using EasyTag on 9.04
I have a sandisk Sansa Mp3 player and have downloaded an audio book in Mp3.
The problem that I am having is that the 'book' chapters don't play on the sansa in the correct 
order. So I opened up EasyTag and changed the tags etc. using ID3 v.2.4 but no joy. The 
'book'/Album is still listed as 'Unknown' and the playing order is still not correct.

Is there something I'm missing?

Blessings,

Nigel