I'm trying to set up exchange interop, I have OWA and IIS access to public folders set up. I have tried several setting (basic, form, and different mail admin accounts) also tried http://servername, servername, http://servername/exchange, but I keep getting this error:

Server error encoutered
Message: system failure: java.lang.NullPointerException: Name is null
Error code: service.FAILURE Method: CheckExchangeAuthRequest Details:soap:Receiver

Any Ideas?