Books Tag cloud

I can only imagine that this is a bug, but it may be intended. When I view the tag cloud of my book's tags, all the tags are the same size despite there being different numbers of them, ie. 7 books are tagged 'fiction' while 1 is tagged 'crime' yet the tags appear to be the same size in the tag cloud.

It works for music, but just doesn't seem to work for books...

It's because most of the tags are only used once or twice and there is not much spread. I have added to my bugs list.