Okay, So it is not that someone can't rate a admin. The issue is the rating(Stars) changed?
This is a known issue with the current algorithm that the star rating can get a little screwy.
Several of the Beta testers here had a five star rating then all of a sudden they changed to a three star rating a while back.
I know Rick is aware of this. Just don't know if it will be addressed in version 8.0