错误消息401.2。：未授权：由于服务器配置登录失败。部署应用程序时

I have an asp.net 4.0 application that works fine running under cassini but when i deploy to IIS i get the above error. It is running under the Default App pool which a number of other apps use and work fine. Here is a copy of my web config which may be the source:I have an asp.net 4.0 application that works fi