Cisco 7940 no outbound calls but inbound calls working

Hi!!!

This is my case… I have two frePBX boxes located in different cities.

I have a Cisco 7940 phone that I configure 1st for just one PBX and it is working fine.

The problem is trying to make my phone works with the 2nd PBX and obviously another different extension (configuration).

I got registered, and I can receive calls from other extensions, but I am not able to call any other extension.

Any ideas???