Users and Devices

I am having problems with my system at the moment where users and devices have been enabled and when I login to a phone using *11 and extension number and password it sets all my users with the same extension. If another user logs in then all extensions have the same number. The system has 12 Sangoma extensions and a Xorcom 24 astribank and this happens over all the extensions. I can logout with *12 on one phone and all users are logged off and then when I do *65 there is no extension number given.