Hi Jon,
I think the problem you might be getting is the rating control is a bit messed up at the moment when you search for an artist. Am I right that you searched for that artist, rather than it appeared in the list by itself? If so, it's now on the bug list, and we hope to have a fix by next week. If not, can you give mesome more detail on what you did. We can't find those artists in our database!