If it is the one I now see (in a copy I made while investigating), then it is some distance from the extra long line. Apparently firefox and other browsers will treat a </center> (for example) as implicitly closing other structures started within, while IE apparently treats each tag pair as independent. Or at least that's my best guess on why it behaved that way.
Edited by Admin, : Use literals for the HTML tag that's in the text so it's visible.
Sorry about the confusion over rules. I should have included a link (done now with editing). On the top of most forum pages, there is a line of links "Profile | FAQ | Rules | ...". The rules are listed in a different order on the front page link.