There’s a few ways to redirect a page in PHP. Well, two. A right and a wrong.
header('Location: foo.php ');
header('HTTP/1.0 302 Found'); header('Location: foo.php '); exit;
This is evident on IIS6 and IIS7 where the wrong redirect will just fail.
Even if you are not using IIS6 or IIS7 its good practice to set the headers correctly and exit the script.