The request failed with HTTP status 401: Unauthorized.

[Calla]

I'm having trouble with a website when it comes to the authorization. I have one site, called GUI, using a webservice, called WS that requires the user to log on using windows autentication. In the IIS I have set the Directory Security to Integrated windows security (for both the GUI and the WS sites). In my web.config files (for the GUI and the WS) I have the following lines:

<authentication mode="Windows"/>
<identity impersonate="true"/> 

When I enter the URL in IE I get prompted for User name and Password, and I'm sure I enter the correct ones but I still get the The request failed with HTTP status 401: Unauthorized. message. I am running the same web sites on another machine where I use the Enable anonumous access in the IIS and this (of course) works fine. Does anyone have any idea of what might be the issue here?