That's weird. What version of IE are you using? I just tried the one with Win7 and it worked fine. Maybe old flavours have issues with my design?
Here is RetroCopy's website browser stats.
Firefox 54.8%
MS Internet Explorer 33.5%
Opera 4.3%
Google Chrome 4%
Considering most people use FireFox and 80% of the IE users are on IE8 it shouldn't be a problem for most. I'm not going to go out of my way to support IE5/6 when they don't support standard HTML/CSS.
http://validator.w3.org/check?uri=http://www.retrocopy.com/forums.aspx
BTW someone else had an issue once with forums appearing blank, clearing their cache fixed it. Don't know if that helps or not. Thanks for reporting the issue though, it's good to know such things.