Problem with authentication on java ws

Question

Hi, I have application in C# that consume Java WS. Everything worked fine until WS was configured to use authentication. Now I should user login i password to execute methods from WS but I'm not sure how to do it. I've try

var client = new MyBeanClient();
                    client.ClientCredentials.UserName.UserName = "admin";
                    client.ClientCredentials.UserName.Password = "";
                    client.addConsumer("whatever", "", "", "");

But I get SecurityMessageException-{"The HTTP request is unauthorized with client authentication scheme 'Anonymous'. The authentication header received from the server was 'Negotiate,NTLM'."} InnerException - (WebException) - {"The remote server returned an error: (401) Unauthorized."}.

What's wrong?

Thanks