Registering blackberry devices


I am trying register blackberry devices with freepbx extensions. I have setup a wireless router and connect all blackberry devices to it. I managed to successfully register 1 blackberry device. But I cannot register any other blackberry devices at all. I would appreciate if anybody can direct me to troubleshoot the problem.
Thank you.

You need to provide much more information if you expect help.

1 - FreePBX and Asterisk versions
2 - Type of install (distro or hand rolled)
3 - Type of SIP client on Blackberry
4 - SIP error traces from Asterisk
5 - Can the voice server ping the blackberry devices
6 - FreePBX extension configuration

How can you expect anyone to help without providing data?