Index: wp-includes/theme.php
===================================================================
--- wp-includes/theme.php	(revision 11167)
+++ wp-includes/theme.php	(working copy)
@@ -162,6 +162,9 @@
  * @return array Theme data.
  */
 function get_theme_data( $theme_file ) {
+	if( !function_exists( '_cleanup_header_comment' ) )
+		require_once( ABSPATH . 'wp-admin/includes/misc.php' );
+	
 	$themes_allowed_tags = array(
 		'a' => array(
 			'href' => array(),'title' => array()
Index: wp-admin/includes/plugin.php
===================================================================
--- wp-admin/includes/plugin.php	(revision 11167)
+++ wp-admin/includes/plugin.php	(working copy)
@@ -66,6 +66,9 @@
  * @return array See above for description.
  */
 function get_plugin_data( $plugin_file, $markup = true, $translate = true ) {
+	if( !function_exists( '_cleanup_header_comment' ) )
+		require_once( ABSPATH . 'wp-admin/includes/misc.php' );
+	
 	// We don't need to write to the file, so just open for reading.
 	$fp = fopen($plugin_file, 'r');