Confirming (Firefox 1.5.0.1).
I believe the problem is that the browsers think it's UTF-8 although it's actually some sort of Latin-1 (ISO-8859-1 or windows-1252 or whatever). It must be a problem with the new server: The HTTP header says "UTF-8" and the HTML source says "windows-1252". But the "real" HTTP header has a higher priority than the "http-equiv".
If I download the pages with wget and read them locally, there's no problem at all which is quite clear because there's no HTTP header anymore. So the identification in the HTTP header and the actual encoding must match, either by changing the HTTP header to windows-1252 or by converting the whole forum to UTF-8.
As a temporary solution, you can force a different encoding in your browser. It's under the "View" menu in Firefox. Try "Western (ISO-8859-1)", "Western (ISO-8859-15)" or "Western (Windows-1252)".