[RCU] Invalid Post

I just installed roundcube and I am getting the following error after I try to login. I don't see any errors in the log file.

Any suggestions as to what could be wrong? This is on a windows server.

The page you are looking for cannot be displayed because an invalid method (HTTP verb) was used to attempt access.

Please try the following:

• Contact the Web site administrator if you believe that this request

should be allowed.

• Make sure that the Web site address displayed in the address bar of

your browser is spelled and formatted correctly.

HTTP Error 405 - The HTTP verb used to access this page is not allowed. Internet Information Services (IIS)

List info: http://lists.roundcube.net/users/