Aha...dalecosp, I think you are right -- and I wouldn't even need to have localhost return anything. The problem I'm having is that the request to qnsr.com is being routed to 127.0.0.1 and, rather than a 404 response returning immediately, there is no local web server running so the request times out -- and the page waits to load until this timeout finally takes effect...or something.
So here I am contemplating whether to install a web server on one of my workstations to get PHPB to load more quickly. Seems rather drastic I think.