[Freeswitch-users] Unintended call termination

I see that this problem occurred back in January 07 and again in May 07, but I could not find the answer :(. I make a call using a Grandstream Budge Tone 200 IP phone and as soon as the receiving end picks up the call it is terminated. It does not matter what the destination of the call is: mobile, landline or another internal handset. I have put a copy of the freeswitch log at: http://pastebin.freeswitch.org/3187 I have used this phone successfully with an Asterisk installation so believe that it works fine. I have also received calls with this phone via freeswitch, it is just when I use it to make a call that I have this problem. Any ideas/suggestions ? Regards, Craig.