Use extensions CID by forwarding

We use asterisk 1.4.35 and the latest freepbx 2.8
When we forward calls (database or followme) the new outgoing call is setup with the CLI of the caller.
We use a siptrunk and are allowed to setup calls with our own numbers.
In de dialparties.agi I found:
// From this point forward, Set KEEPCID in the channel so subsequent calls, CF, etc. retain the incoming
// CID that get sent down channel local.
$AGI->set_variable(’__KEEPCID’,‘TRUE’);

So I changed it in:
$AGI->set_variable(’__KEEPCID’,‘FALSE’)
And made it read only.
Even after a restart of the server still no change.

When I call to the extension with cellphone 0647954905 it is setting up a call from the calling cellphone to the cellphone the extension has a forward for.

The provider is not happy that we setup calls from numbers we dont own and told us to stop it.
Anybody here with suggestions?

With Ngrep I get this:
U 2010/09/08 08:57:19.594552 our pbx:5060 -> provider:5060
INVITE sip:31613991504@provider SIP/2.0.
Via: SIP/2.0/UDP our pbx:5060;branch=zxhG4bK7b9c9266;rport.
From: “0647954905” sip:[email protected];tag=as392b951f.
To: sip:31613991504@provider.
Contact: <sip:0647954905@our pbx>.
Call-ID: [email protected].
CSeq: 102 INVITE.
User-Agent: Asterisk PBX.
Max-Forwards: 70.
Date: Wed, 08 Sep 2010 06:57:19 GMT.
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO.
Supported: replaces.
Content-Type: application/sdp.
Content-Length: 182.