The following is a response I received from our publisher support people:
"The "NT" phenomenon occurs for end users who are using older versions of IE9 (Microsoft has fixed it in the newest release).
The solution is to update the MSIE 9 browser or... to enable the "compatibility mode" on their existing IE9 browser."
I am told that is the computer-illiterate version of what is happening. However, a simple solution was granted: "Use the compatibility-mode on your browser."