"Play next song" doesn't play next but first song of Library

Whenever I import new music, "Play next song" doesn't play the next song but starts again with the very first songs of my iTunes Library. These also show up in the "Play next song" list. I may delete them from there, but with the next imported CD, they're back again.

Only workaround so far: To manually restart the first of the new songs playing; *then* iTunes continues correctly. But this is idiotic.

Any solution for this?

Thank you very much!