Index: branches/5.1.x/core/kernel/utility/socket.php
===================================================================
diff -u -N -r13086 -r14201
--- branches/5.1.x/core/kernel/utility/socket.php	(.../socket.php)	(revision 13086)
+++ branches/5.1.x/core/kernel/utility/socket.php	(.../socket.php)	(revision 14201)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: socket.php 13086 2010-01-12 19:47:40Z alex $
+* @version	$Id: socket.php 14201 2011-02-15 16:58:03Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -266,7 +266,7 @@
 	            return $this->raiseError('not connected');
 	        }
 
-	        if (is_null($blocksize) && !OS_WINDOWS) {
+	        if (is_null($blocksize) && (substr(PHP_OS, 0, 3) != 'WIN')) {
 	            return fwrite($this->fp, $data);
 	        } else {
 	            if (is_null($blocksize)) {