diff /includes/content.inc /includes/content.inc
--- /includes/content.inc
+++ /includes/content.inc
@@ -277,10 +277,6 @@
 
     $content = $function($subtype, $conf, $args, $pane_context, $incoming_content);
 
-    if (empty($content)) {
-      return;
-    }
-
     // Set up some defaults and other massaging on the content before we hand
     // it back to the caller.
     if (!isset($content->type)) {
@@ -291,6 +287,10 @@
       $content->subtype = $subtype;
     }

+    if (empty($content->content)) {
+      return $content;
+    }
+
     // Override the title if configured to
     if (!empty($conf['override_title'])) {
       // Give previous title as an available substitution here.