I will start tracking the ones that come back. It is possible that I am having connectivity problems on occasion and maybe it isn't registering because of it, but it is not the case every time. Obviously I don't listen through them again, but often I am working on a project (woodworking) and the music is playing, when I realize I have heard what is playing before so when I go over to the computer I will see it was a CD I already marked complete.