I figured it was okay. I thought at first the problem might be that I'm using HTML 4.0, and Netscape 4.x only supports up to HTML 3.2. But it works fine in Lynx, and should degrade gracefully. The general consensus there seems to be that version 4.x sucked. But still, I'm committed to being usable by all browsers, so I started poking around some more.
Misplaced graphics keep changing where they are misplaced.
When hubby's up, I'll ask if he knows any way I can fix it. But as far as I can tell, the problem is Netscape 4.x is severely buggy. I'll post here if I find a solution.