I am having CSS problems. :-(

Your security checkpoints are overwriting text. Ditto your inlined <tt> text, it aligns itself without paying attention to the surrounding text. Perhaps that should be a class? Generally mixing inline and external CSS is supposed to be a bad idea.

As for CSS and browser bugs, what I have seen done with Apache to get around them is that the stylesheet is served by an Apache handler that does a browser detect for things that really cannot be worked around. It works but...

Oh, and a useful trick to think about. Get a computer with VMWare installed. IE 4, 5, Netscape, Netscape under Linux, etc quickly adds up to a lot of partitions to juggle, and reproducing a setup can be a pain. But keeping that many virtual machines is fairly easy to do for a fraction of the pain. And working from a snapshot you can reproduce situations reliably and easily.