I have installed trixbox (2.0), running Freepbx 2.2.0rc3. There are 3 outbound zaptel channels (zaptel-1.2.10). Frequently the dialed number gets connected to a wrong number. When I look at the logs it shows the correct number, If you hook up the line to an ordinary phone, this problem doesn’t occur.
what ever your issue is - you are running a buggy pre-release of FreePBX. You should upgrade that regardless and then if/when your problem persists, seek help.