fixed errant syntax in changeset 53ace78c4b45, fixes #37
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index d7cf236..b3c625e 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -855,7 +855,7 @@
 
 		$CI =& get_instance();
 		
-		if ( ! is_object($CI->security))
+		if ( ! isset($CI->security))
 		{
 			$CI->load('security');
 		}