Callback not writing to config file

I am running PBX in a Flash with latest freepbx 2.4.0 and asterisk 1.4
Callback module is installed everything looks ok in freepbx but it does not write anything into extensions_additional.conf.

I have uninstalled the module completely (deleted folder from /var/www/html/admin/modules/) then reinstalled so it would grab the latest from the web.

Should it be writing a callback context into extensions_additional.conf?

Any help appreciated