I'm finding the same - can't select any favorites.
I'm also on Win7 64bit and running latest FW 15.06.
are you trying to select favorites from the right side? those are files already on your axe.
the favorites function is to help you select the new files you are auditioning from your computer, in the Left side, the Browser panel. i was just demoing the new features in my live video chat for a few people, but i have to head out for now.
i'll be back though and can show you how it works. i'll probably make a short youtube video as well sometime this week.