I don't think this is an issue with pagination. I bet if you guys tried a browser other than IE, these issues would magically go away.

The problem is that whenever someone copies and pastes their posts from Word, it introduces a bunch of garbage that, ironically, Microsoft's own browser can't deal with, and it breaks everything that follows that post on the page. In fact, I doubt you're simply missing pagination. I bet if you count the number of posts on the page, it's often less than the "posts per page" setting in your control panel.

This is a long-standing issue and something I've tried to filter out with varying levels of success. Still working on it.