Works great now.
In case it helps, there is one little thing that doesn't make sense that I tried. I opened a command-line window and pinged
www.hexcode.co.za yesterday when I couldn't get a web page from that address. The ping worked fine with a time of about 47 ms with 0% loss. Now that the site is working fine, I tried it again. It was the same result.
This is telling me there was something wrong with only the Web server on the server itself.