Thanks for your reply.
Yes, I also re-scanned all files in the library.
I also ripped the original CD again, but still got the same result.
My neighbor has a CD of the same album, another release that I borrowed and ripped with the same result.
So it's not that this particular track is damaged on my end or anything like that.
It must be a bug in the MusicBee settings or the database I think.
It would be good to know which file contains the information for the Top Rated playlist as this is driving me crazy now.
Suggestions to fix this problem are very welcome.