Can't view forum......Help?

I am a member of the Lefora forum for "Code 3 Collectibles", and I have a little problem.   Ever since the most recent Lefora upgrade a few weeks ago, I am unable to view that particular forum on my own home computer.   All that will load is the masthead at the top of the page.   The rest of the browser window remains blank white.   Strangely enough, I CAN, however, view this Support forum, but can't post on it (I am posting this from my parents' home.).  

I am running an older iMac (bought new in early 2001), with an early version of OS X, which was an upgrade from the 9.something that came installed in it.   Browsers used are Safari, Netscape and Internet Explorer.   I've never been the "techno geek" type, who keeps right up with the latest and greatest.   I am more the type of "as long as it does what I need it to do, all is good".   Well, unfortunately, all is not good any longer, and I fear that I am stuck now.   And, not just on the forum in question, either.  I am afraid that my machine is simply too old and outdated to be compatible with the latest upgrades.  

Is there something that somebody can recommend for me to try, so that I may continue to view and participate on the Code 3 forums, or am I, as the expression goes, "S.O.L." until such time as I can afford a new computer?  

Any help or feedback will be appreciated.   Thanks in advance.