Problems with the Header function

Hi there, I'm using PHP with Windows 2k Adv. Server (IIS). I'ma having a problem in some executions of the function Header. Sometimes it returns me an error. I.E. header("Location: alertas.php?erro=3&ti&tip=$tip"); exit; i got this error: CGI Error The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are Once more i say that this error only occurs sometimes and not always. I don't send anykind of HTML before the Header function not even a blank space. As i'm having a co-worker with this problem too, and he isn't registered in the ML (YET) in the reply add as a CC artur@mni.pt Thank you. Hugo Dias Web-programmer MNI - Médicos na Internet www.mni.pt www.saudenainternet.pt www.listamedica.com MNI- Um mundo de médicos