Yeah, the whole genre relating thing isn't perfect yet. Hence why it's called the "music genome project."
Obviously there's some issues like, for example, Incubus' new album sounds NOTHING like their old ones, so of course it's going to be a little off if you just type in "Incubus" and expect it to do all the work for you.
They label groups with their crazy categories, not albums or songs.
I think the categorization in general could be better, too. There's a lot of aspects of music it doesn't address at all, but maybe I'm being picky, there.
But regardless, I've been turned on to 4 or 5 new bands so far, thanks to Pandora.