Citrix online plug-in could not contact the server

Hi,

I am a newbee to xenapps 6.

We are trying to setup a hosted solutions for applications. I have got the setup as below.

One physical server running Microsoft Windows Server 2003 R2 as domain controller.
Another physical server running Microsoft Windows Server 2008 R2 (member of domain) where I tried to install Xenapp server/Web Interface/ License Server.

I have followed the link below to install the server.

http://www.danieletosatto.com/wp-content/uploads/2010/04/howto_install_configure_xenapp6_server_with_webinterface_license_server.pdf

and the link below to host the application.

http://aaronwalrath.wordpress.com/2010/04/09/configuring-clients-for-citrix-xenapp-6/

At the final step, when I try to enter ther server address, It kept giving me the error message stating that
"Citrix online plug-in could not contact the server".

Any thoughts in fixing this issue would be highly appreciated.

PS: These servers are not connected to the internet. All these setups are done on a test environment.
I have also checked that the windows firewall on both the servers are turned off.