Bump. I’m trying to get this project finished for the client, and neither one of us have seen this problem. Nor have we found a solution yet.
Oddly enough, I was able to fix the error by temporarily activating PHP 5.x on that server. However, that also broke some plugins, so I restored it to PHP 4.x and was still able to click on the Manage > Akismet Spam link, however it is not known if the problem will return once Akismet starts catching more spam.
