Index: wp-content/themes/twentyeleven/comments.php
===================================================================
--- wp-content/themes/twentyeleven/comments.php	(revision 18052)
+++ wp-content/themes/twentyeleven/comments.php	(working copy)
@@ -12,6 +12,14 @@
  * @since Twenty Eleven 1.0
  */
 ?>
+
+<?php
+/* Return early if post_type does not support comments. */
+if ( ! post_type_supports( get_post_type(), 'comments' ) ) {
+	return;
+}
+?>
+
 	<div id="comments">
 	<?php if ( post_password_required() ) : ?>
 		<p class="nopassword"><?php _e( 'This post is password protected. Enter the password to view any comments.', 'twentyeleven' ); ?></p>