Just tried it on my shiny new IE8 installation, and it's working ok.
Last question: when you have to log in, is this on visiting the main beoir.org page, or when you follow a link to the forum (for example, in a new post notification in a thread).
Did you try purging your cache etc?
(these last questions are going the way of the Spanish Inquisition).
Can you try it on a non-work machine?