Index: privatemsg.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/privatemsg/privatemsg.module,v
retrieving revision 1.70.2.30.2.91.2.44
diff -u -p -r1.70.2.30.2.91.2.44 privatemsg.module
--- privatemsg.module	26 Apr 2009 22:16:08 -0000	1.70.2.30.2.91.2.44
+++ privatemsg.module	29 May 2009 11:00:53 -0000
@@ -1645,10 +1645,28 @@ function _privatemsg_list_headers($has_p
       $header[$key] = $return;
     }
   }
+  if (count($header) <= 1) {
+    // No header definition returned, fallback to the default.
+    return $header + _privatemsg_list_default_headers();
+  }
   return $header;
 }
 
 /**
+ * Table header definition for themes that don't support theme patterns.
+ * 
+ * @return
+ *   Array with subject, participant and last updated definition.
+ */
+function _privatemsg_list_default_headers() {
+  return array(
+    'subject' => phptemplate_privatemsg_list_header__subject(),
+    'participants' => phptemplate_privatemsg_list_header__participants(),
+    'last_updated' => phptemplate_privatemsg_list_header__last_updated(),
+ );
+}
+
+/**
  * Formats a row in the message list.
  *
  * Does use theme patterns to display the single fields.
@@ -1672,10 +1690,27 @@ function _privatemsg_list_thread($thread
       $row['data'][$key] = $return;
     }
   }
+  if (empty($row['data'])) {
+    $row['data'] = _privatemsg_list_default_thread($thread);
+  }
   return $row;
 }
 
 /**
+ * Table row definition for themes that don't support theme patterns.
+ *
+ * @return
+ *   Array with themed subject, participant and last updated fields.
+ */
+function _privatemsg_list_default_thread($thread) {
+  return array(
+    'subject' => phptemplate_privatemsg_list_field__subject($thread),
+    'participants' => phptemplate_privatemsg_list_field__participants($thread),
+    'last_updated' => phptemplate_privatemsg_list_field__last_updated($thread),
+ );
+}
+
+/**
  * Menu callback for messages/undo/action.
  *
  * This function will test if an undo callback is stored in SESSION and execute it.