[Staxed]

this explain it?

Originally Posted by phpfreaks.com

max_execution_time integer

This sets the maximum time in seconds a script is allowed to run before it is terminated by the parser. This helps prevent poorly written scripts from tying up the server. The default setting is 30.

The maximum execution time is not affected by system calls, stream operations etc. Please see the set_time_limit() function for more details.

You can not change this setting with ini_set() when running in safe mode. The only workaround is to turn off safe mode or by changing the time limit in the php.ini.

Your webserver can have other timeouts. E.g. Apache has Timeout directive, IIS has CGI timeout function, both default to 300 seconds. See the webserver documentation for meaning of it.