This was something that just stung me. Using a smart playlist, I only load songs onto my ipod that have a 1 star rating. Just a quick way of being able to take songs or albums off, or add ones quickly. But I just went to update my list (get some old now boring songs off), and after making some tracks zero ratings, the songs wouldn't remove it self from the list.
If I went into "Grid" view, and then "Albums", and highlighted all albums, then the "Album Rating" option showed up in the right-click menu. From there I made them all zero ratings. I was now able to go back and adjust individual songs correctly, and they dropped out of my listing.
I can see some people liking this "Feature". But i'm certainly in the boat of people wanting this as something you can turn off if you want...
Hope this method works for others.