Thank you, Chris. The new template did not include a page comment form, but the theme author–with an amazingly quick response time, I might add–gave me a line of code to insert in the page.php file that enabled the comment form again.
Basically, according to the author, the fix for this issue is to insert the following line of code at line 13 on the page.php template:
<?php comments_template(); // Get wp-comments.php template ?>
I did that this morning and it works perfectly.