Chatbox page bug

I went to PM a user who I was chatting with in the chat box earlier by checking out old chatbox messages on the "view all posts" chatbox page, and got this page:

http://xtreme-jumps.eu/user.php?id.SwiftSpear

When it should have linked this page:

http://xtreme-jumps.eu/user.php?id.9225

I couldn't find the code to generate the chatbox items. I'm guessing there's a template management system somewhere that fills that information out? It's a super trivial fix if the code section can be found.