The users do not see each other

Hello,

I installed ejjaberd 2.1.2 on a Windows Server 2003. I have set up in groups as it says in http://www.ejabberd.im/shared-roster-all shared so that all users will see with all the others. As a client, I use pidgin, pidgin users are created on the server alone to self-registration.
My problem is that despite http://www.ejabberd.im/shared-roster-all fact, my users are not among them. On the server if I appear online.
What can I do?
If my network jabberd going to be local, do I need to open some ports in the firewall that I have for internet?

Thank you very much