I needed to share this with someone:
Don't use underscores('_') in your custom style (class) names with CSS. Netscape 4.x does not recognise the style if you do (at least it doesn't with LINKed external style sheets).
For example:
<LI>If you call a custom style '.article_text', the style formatting will not be applied in Netscape (it will however work in IE5).
<LI>'.articletext' will work in both Netscape 4.x and IE5 (and maybe IE4?)
So avoid using underscores in stylesheets. Hope this helps someone somewhere sometime.