While standing on the Amazon website that the songs "easy" and "Good To Be Gone" are only available on the album (CD), I saw in retrospect that they were in the download package.
I do not know why this is so - but even when both songs were not there, it would not bother me (1 because I was assuming that they do not have it anyway and 2. because they are not the most important and famous songs of Sugababes belong).