Well....looks like I misdiagnosed the problem.
I was using php to set the stylesheet based on the browser. When the stylesheet wasn't being invoked properly, I incorrectly assumed the php wasn't working. But really the issue is since I got the 401 by trying to access a subfolder, it looks like I was no longer at the root level, even though my 401 page was located there.
Clear as mud, I know. Specifically, a simplified version of my page had this code:
<?php
echo '<link rel="stylesheet" href="styles/sdi3column_allbrowsers.css" type="text/css">';
?>
Note that "styles/sdi3column_allbrowsers.css" is assuming I'm at the root level. (My 401 page IS at the root level).
If I got the page by calling it, http://www.silverleafdesign.com/unauthorizedtest.php, the page rendered fine. However, if I got the page by going to www.silverleafdesign.com, clicking on Client Login, and then hitting Cancel, the page did not find the stylesheet.
However, when I changed the path of the stylesheet in the 401 page to "/styles/sdi3column_allbrowsers.css" (added / to the front), then the page rendered correctly when I got there by trying to log in.
Do you know why this would be the case? Logically, since the 401 page is at the root level, I would think that "styles/sdi3column_allbrowsers.css" would work correctly, but it didn't until I add the /. Why would this be?
Thanks, Susie