I have a very strange problem. in last few days i saw too many "Premature end of script headers" in apache log file cat /usr/local/apache/logs/error_log |grep "Premature end of script headers" |wc -l 4190 Its happens only on php files perl cgi scripts are working just fine. Right now i am with last php version but sill have that problems. php -v PHP 5.2.9 (cgi-fcgi) (built: May 19 2009 07:04:00) Copyright (c) 1997-2009 The PHP Group (php scripts are runing with suphp . ist updated too ) In addition to that i try to remove ulimits for all users on the system , removed a RLimitMEM 2003933525 and RLimitCPU 240 from the httpd.conf Unfortunatly that did not help at all .. Then i try to change semaphores sysctl -a |grep sem kernel.sem = 350 32000 32 128 ipcs -a |grep nobody |wc -l 15 But nothing changed .. I double checked for a big log files dont have such files, Right now i am in dead end. Dont have any ideas what can be wrong. I will appreciate ny ideas or suggestions.