An amusing bug, if only because it took a few minutes to debug as opposed to a few hours.

If users navigated to the newly updated PHPMyFAQ server by name, they layout was broken – but going to it by the IP address would have no such effect.  There was no weird javascript issue that differed between the two.

It turned out that the server name was listed as an Intranet site, and was being displayed in a different display mode than if one would navigate to it by the IP address alone.  Disabling intranet auto-detection resolved it, but I am not really sure WHY it happened.