iis header redirect does not update url

Hi everyone, I'm porting an application to an iis server. There is a login process on the app which looks like this: enter username & pass into a form -> submit to a login script which verifies user/pass on failure -> go back to login form on sucess->redirect to wherever the login form wants to go (there are several different logins, all using the same verification script) the login redirect looks like this: if(!$redirect) $redirect = HOMEPAGE; header("Location:".$redirect); pretty simple right? my issue is, the login works and the redirect to the new page is made. however, the url of the new page as listed by the browser is the same as the old url of the login script. to be specific: the login form is located at "/user/index.php" the login script is located at "/lib/login.php" the final page (where you are redirected upon login) is at "/user/home.php" when the login succeeds you find yourself correctly at "/user/home.php" except the browser still lists "/lib/login/php" as the current url even thought the content reflects "/user/home.php". This has the unfortunate effect of breaking every relative link on the user home page since the browser thinks it is in the wrong directory. has anyone run across this before? is there a different iis redirection method? Thanks very much for any help, -jonathan