Category page problem

Being a wiki newbie, I don't know the cause, but the category pages don't display properly on my browser. (Mozilla) The listing of sub-categories and articles in the category doesn't start until after the left hand menu box. This leaves LOTS of white space and the impression that there is so list. I've also checked IE and Opera, and they have issues as well. What browser is everyone else here using? Or maybe it's because I'm running under Win98. -- Lyle Greg Lisle