Isn't that lame of them though? I mean there was only 16 songs on the CD, there was plenty of room for those songs.
Apparently, the folks who put the CD together decided that they needed to make as much money off of it as they could. The production studio put out three versions of the CD, all with different numbers of song on them.
Just read the first review towards the bottom of the page here
bastids
ZemRrushe
I wouldn't worry about it much if I were you, I'm sure their going to release a second CD of music from the movie, they tend to do that with this type of film.