Headers sent error msg on one server but not the other...

Hey Folks, I have a script that times out the session if there is no activity in a certain amount of time. If there is no activity the HEADER() redirects to the logout page and kills the session. Everything works fine on our test server, but when I test the script on the production server, I get an error "HEADERS ALREADY SENT..." after no activity. I know all this stuff needs to be on top, before any XHTML. The test server has reg globals = OFF and the production server has them set to ON. I can't change the any PHP.INI settings on the production server. Both servers are running PHP 4.3.10. Other than that PHP installation is close to identical. Any ideas / thoughts on what's causing the production server to send this error out? Something to steer me in the right direction... I'm attaching a code snippet to look at: if (mysql_num_rows($result) > 0) { $_SESSION["valid_user"] = $email; } elseif ($t_timestamp < $c_timestamp) { HEADER("Location: logout.php"); exit; } Best, CH ______________________________________ Craig Hoffman ICQ / iChat: m0untaind0g ______________________________________