[drupal-support] error 500 and menu module

I keepting getting eror 500 in the menu module. Any pointer to wht mmight be wrong welcome . I have reproduced the error below, Server error! The server encountered an internal error and was unable to complete your request. Error message: Premature end of script headers: index.php If you think this is a server error, please contact the webmaster. Error 500 - Larry