asp:LoginName Not Me

I am using VS2010 and an asp control: LoginName.  The LogInName control does not display the correct user.  I am using windows authentication and this is what is in the web.config.

 
<authentication mode="Windows"/>
    <authorization>
      <deny users="?" />
    </authorization>

Sometimes when I open the page I get the popup control even though it an internet site and passing my credientials.
Could this be a server setting?  Anonymous access is turned off on the server and Integrated Security is on.

Any Ideas?