Isn't it typical of Amazon that they put in a new system and it's as glitchy as hell?
As Vanessa said the global review count doesn't match on the different sites. Ever since they started accepting only ratings, even on a book's product page, the number of reviews was often way off. It might say 8 reviews, then there'd be 12 ratings, but only 6 actual reviews.
I can't see how this helps buyers - it certainly doesn't help authors any more. I used AC to keep track of reviews and, to a lesser extent (because of the time lag) ranking. Easy to see, at a glance, what had changed, but now that's virtually impossible. Bah! I do wish Amazon would stop fiddling - or at least ask us first if it's a change that we want.