Login page not rendered correctly IIS

Question

I want to run my page on IIS , I used default template in VS 2010 (NET4) (with prebuild web forms for login and password). Authentication works fine and I get redirected to Default.aspx (which is displayed correctly). Problem is when I first go to the site I get this start login (accounts/login.aspx) screen (jpg in attach) which isn't rendered correctly. Why is that?

Once authenticated all forms are rendered fine (even accounts/login.aspx)

I don't get this problem when use classic web development server from VS2010

Thanks in advance