SLG, I try to test everything before it is launched on both a PC and on the Mac. I cannot understand the reason for your problem though.
I have run Explorer and Netscape on an old LC475, PowerBook 1400, Motorola StarMax, iBook and G4 with various operating systems with no problems. Currently running on the G4 with both Netscape 4.76 and Explorer 5.0 with MacOS 9.1 and Explorer 5.0 with MacOSX and no problems. I can only assume that the problem you are experiencing is something to do with the way your browser is set up for java.
There is a new Mac OS Runtime for Java MRJ 2.2.5 which you can download from Apple at
http://asu.info.apple.com/swupdates.nsf/artnum/n11927
Also you should try the iCab browser. You can download that at
http://www.icab.de/. This takes up a tiny amount of memory when loaded and has numerous features.