Index: wp-admin/includes/file.php
===================================================================
--- wp-admin/includes/file.php	(revision 8954)
+++ wp-admin/includes/file.php	(working copy)
@@ -482,9 +482,9 @@
 
 function get_filesystem_method($args = array()) {
 	$method = false;
-	if( function_exists('getmyuid') && function_exists('fileowner') ){
+	if( function_exists('posix_getuid') && function_exists('fileowner') ){
 		$temp_file = wp_tempnam();
-		if ( getmyuid() == fileowner($temp_file) )
+		if ( posix_getuid() == fileowner($temp_file) )
 			$method = 'direct';
 		unlink($temp_file);
 	}