I have very similiar problem. Cisco GK cannot start working with Clarent GK (v. 1.3.4).
I did every necessery things – creating static route in server_info, profile in gateway_profile, call routing and rating, also zone remote and zone prefix on Cisco GK – but without success. Sb tells me that with 1.3.13 it works. Maybe sb have that soft version or have some idea how to set it working.