Thanks Chronon. I understand what is going on now.
You are totally right... on choosing album.. and then playing it.. the tracks do play according to the track number.
What I was doing, was choosing the artist.. and then "all tracks".. thus getting the tracks in the album in alphabetical order.
Since I only had 1 album for this artist, choosing "all tracks" seemed reasonable to me. I guessed wrong!

Thank you all for your help
