I am aware of the problems with Netscape v4.xx.
I worked for awhile to get the things to work with it, but I finally just gave up. The older Netscape just can't handle the complex tables that the forum software generates. The options were either to leave the forums looking "stock" to ensure Netscape v4.xx compatibility, or to just design for the newer generations of browsers, and we chose the latter.
All I can tell people is to upgrade to Netscape v6.xx or to Internet Explorer. If you are running Windows 95, Netscape 6 will not run correctly (or so I am told) so you'll need to download Internet Explorer v5.5 (which is still available from Microsoft).
I really see no reason for people to be running the old Netscapes anyway, since they are quite problematic and do not support a lot of the newer features of the net. All the other browsers are free upgrades...