Hello, we are using ISA SERVER as proxy to redirect to Websense upstream server Internet traffic allowing delegation of basic authentication credentials. Sometimes, in a apparently random way, instead of rendering the correct page it shows only the text "type1 received". Clients are most of them windows xp users and remote sessions on windows 2003 (about 200 users) We contacted the Websense and they told the problem is Firefox is not working properly. I post also what they said: "The NTLM conversation constitues type 1 packet, where your browser requests the URL. We receive your type1 packet and respond with a type2 packet, requesting the user information (ntlm id). This type 2 packet has the "type1 received" message incorporated into it. What should happen next, is that when your browser receives our type2 packet, the browser should send the type3 packet containing the user information. We then verify the user information and establish the NTLM connection. In your case, the browser is not sending the type3 packet. Instead the browser is displaying the type2 packet information (with the "type1 received"message). The browser should not do this. Generally we would expect this to occur if your browser is corrupted. It may be because of another reason, but it definitely points the problem to be at your end." Is there any way to understand what is happening?