Pop Up does not show - does not "see" header/footer call?

I installed Pop Up but it does nothing.

Right now, I have nothing in it but text for testing. Nothing shows.

Yes, I activated it.

Yes, I tried the Test Head Footer addon. I am getting the messages:
Your active theme:
Is missing the call to <?php wp_head(); ?> which should appear directly before </head>
Is missing the call to <?php wp_footer(); ?> which should appear directly before </body>

However, I looked at the header.php and footer.php and plain as day, there are the calls.

I am using Atahualpa 3.77.

Any ideas?