Client found response content type of '', but expected 'text/xml'. with Wse 2.0

[powerranger]

I created a very simple application which calls a ws which in turns
call another ws and return true. In my Windows application, I have
the following code on the click event


public localhost.Service1 p = new localhost.Service1();
bool test = p.test();

In the Web Service1, I have the following code which calls another Web
service...

[WebMethod]
public bool test()
{
localhost.Auth auth = new localhost.Auth();
bool test = auth.test();
return test;
}


[WebMethod]
public bool Auth()
{ return true; }

I don't undertand why it gave me an error saying:
"System.InvalidOperationException: Client found response content type
of '', but expected 'text/xml'." Thank you for your help!