There appears to be an issue with the pagination of forum threads that contain posts from banned users.  It looks like the banned user's posts are taken into account for the total post count, so when determining how many pages to display for a thread, the divisor is off, and clicking on the last page results in an error until visible post count finally pushes over to the last page.

Error message reads:  "Undefined action."

Can you give an example URL for a thread with this problem?

http://www.alivenotdead.com/bbs/ ... &extra=page%3D1

down to the bottom left of the page, by the page nav there is a post count and page count, it says 174 posts on 9/9 pages.  however, when you look at the actual last post in the thread, it's marked as post 170.  i believe this is because there were 4 posts from banned user MaximusRev.  

So, if you have your page settings to 20 posts/page like I do, when the total post count hits 180+, it will roll over to have 10 pages.  however, due to the 4 missing posts, navigating to page10 will result in an error since there are no visible posts in the 180+ range.

This is a very annoying problem.  I hope a solution can be found soon.

ok, i manually updated the thread counts...should be fixed!