If there are more comments marked as spam than fit one page (and this is almost always the case...), clicking on "next page" below the comments doesn't actually take the user to the next page, it merely shows the same page over and over again. The page indicator claims that you're on the next page, but this isn't actually true. The same thing happens if you use the "previous page" link, or any of the numbered page links between "next page" and "previous page".
As Akismet is by no means infallible, this is a huge problem, because it means you can't actually check if the spam is actually spam, or if legitimate comments have been marked as spam -- you can only check the first 50 comments, because you can't see any of the others.
This wasn't a problem until I upgraded to WordPress 2.5.
