Steven:
Mark this "[Solved]," please. The server and connection speeds were red herrings. Well, they may have come into play -- you know infinitely more about this sort of thing than I do -- but they weren't the real problem.
A little over a month ago, I switched from a free anti-virus, etc., system to a paid suite from Bitdefender. It turns out that if you have the setting Privacy --> Antiphishing --> Show Bitdefender Toolbar set to "On," Bitdefender -- and, yes, I find this hard to believe myself -- inserts code into (at least some) downloaded web pages! In this particular case (my experimenting very carefully this morning with http://www.billanddot.com/victory-xct/ ), it changed...
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<!-- saved from url=(0014)about:internet -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="apple-mobile-web-app-capable" content="yes" />
<script type="text/javascript" src="res/juicebox/jbcore/juicebox.js" charset="utf-8"></script>
<script type="text/javascript"><!--//--><![CDATA[//><!--
new juicebox({
backgroundColor : "rgba(51, 51, 51, 1.0)",
configUrl: "config.xml",
containerId: "juicebox-container",
galleryHeight: "100%",
galleryWidth: "100%",
themeUrl: "res/juicebox/jbcore/classic/theme.css"
});
//--><!]]></script>
<style type="text/css"><!--/*--><![CDATA[/*><!--*/
body
{
background-color: #333333;
margin: 0;
}
body, html
{
overflow: hidden;
}
/*]]>*/--></style>
<title>2012 Victory Cross Country Tour</title>
</head>
<body>
<div id="juicebox-container"></div>
</body>
</html>
...to, in one such test (scroll to the bottom of the code)...
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<!-- saved from url=(0014)about:internet -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="apple-mobile-web-app-capable" content="yes" />
<script type="text/javascript" src="res/juicebox/jbcore/juicebox.js" charset="utf-8"></script>
<script type="text/javascript"><!--//--><![CDATA[//><!--
new juicebox({
backgroundColor : "rgba(51, 51, 51, 1.0)",
configUrl: "config.xml",
containerId: "juicebox-container",
galleryHeight: "100%",
galleryWidth: "100%",
themeUrl: "res/juicebox/jbcore/classic/theme.css"
});
//--><!]]></script>
<style type="text/css"><!--/*--><![CDATA[/*><!--*/
body
{
background-color: #333333;
margin: 0;
}
body, html
{
overflow: hidden;
}
/*]]>*/--></style>
<title>2012 Victory Cross Country Tour</title>
<script type="text/javascript"></script><link rel='stylesheet' type='text/css' href='/B1D671CF-E532-4481-99AA-19F420D90332/netdefender/hui/ndhui.css' /></head>
<body><script type='text/javascript' language='javascript' src='/B1D671CF-E532-4481-99AA-19F420D90332/netdefender/hui/ndhui.js?0=0&0=0&0=0'></script>
<div id="juicebox-container"></div>
</body>
</html>
I downloaded and installed a couple of sniffer programs, but all I had to do was a simple View Page Source to discover this. Sorry about that, but who knew?
BTW, I was experimenting with the latest versions of Chrome and Firefox. What I was doing this morning was clearing each browser's history (for "Today" in FF, my default browser, and since "the beginning of time" in Chrome), and then attempting to load that page. In my testing this morning, I was consistently getting that problem, with Chrome displaying that error message and FF just sitting there, not displaying anything except the background color. As before, an F5 then eliminated the problem each time (in either browser). Following that testing, turning that option off in Bitdefender left the HTML code alone, and the problem went away.
Searching Bitdefender forums reveals complaints about this "feature," but nothing I could find was terribly recent, nor did I stumble across any post where someone reported that it can prevent a page from loading properly. I'll look a bit more, and add my own post there if I don't find anything like that. (Bitdefender seems like a nice suite in other respects, BTW, and gets good marks from testing services, is very quick in its scans, and was cheap enough. And I believe I'm just past the get-your-money-back period, so I guess I'll keep it.)
Bottom line: if anyone else gets that error message, ask if he or she is using Bitdefender and has that toolbar option on, and have the poster take a look at the page source in the browser.
Thanks, as always, for your time and support.
Bill