The onresize fix you mentioned is a well-known bug fix for Netscape 4.x. The browser dumps all CSS properties when the window is resized without this bit of JavaScript, which can be found at webmonkey.com.
Unfortunately, I'm having the same problem with both Netscape 4.77 and Netscape 6.2, and this time the bug fix has absolutely no effect in either version. (The page works okay in Netscape 7 PR1 for some reason, though.) A page will start to load correctly in these two versions, then suddenly revert to a plain, white, unstyled version of the HTML. This is all the more ci\onfusing because I've had similar layouts work fine in v6.2 as-is, and the bug fix has always worked in 4.77 as well. I'm guessing that the fact my current layout is PHP-generated rather than static HTML has something to do with it. I've heard of problems with PHP in Netscape before, but I can't find any concrete explanation for the rendering errors.
Anyone care to take a stab at this one?