Index: install/prerequisites.php
===================================================================
--- install/prerequisites.php	(revision 15437)
+++ install/prerequisites.php	(working copy)
@@ -146,8 +146,10 @@
 			$ret['date.timezone'] = ini_get('date.timezone') != '';
 
 			$ret['variables_order'] = strpos(ini_get('variables_order'), 'GPC') !== false;
-			$ret['output_buffering'] = ini_get('output_buffering') > 0;
 
+			$output_buffering = strtolower(ini_get('output_buffering'));
+			$ret['output_buffering'] = $output_buffering == 'on' || $output_buffering > 0;
+
 			return $ret;
 		}
 
Index: install/step_templates/sys_requirements.tpl
===================================================================
--- install/step_templates/sys_requirements.tpl	(revision 15437)
+++ install/step_templates/sys_requirements.tpl	(working copy)
@@ -30,7 +30,7 @@
 		'error_reporting' => "- error_reporting(...) works (optional)",
 		'date.timezone' => "- ini_get('date.timezone') - timezone set (required)",
 		'variables_order' => "- ini_get('variables_order') - contains \"GPC\" string",
-		'output_buffering' => "- ini_get('output_buffering') > 0 - buffering works (required)",
+		'output_buffering' => "- ini_get('output_buffering') > 0 - works (required)",
 	);
 
 	$output = sprintf($heading_tpl, '<strong>Server-side requirements</strong>');