Sorry to hear some people are having problems. The forum relies heavily on cookies and javascript. If your browser isn't handling them, then needless to say, you're going to have problems navigating the site.
- If people are having log-in problems then I suspect it's a cookie issue.
- Internet Explorer: Check the security level.
- Firefox: Tools->Options->Privacy->Cookies
- If people can't click on smilies then it's probably a javascript issue. Check to see if you haven't disabled javascript (or javascript/ad blocker/etc. for iceinspace).
Apart from that, I'm sorry but there's not much I can do about cookies and scripts from this end.