Asterisk Upgrade

I was Using freepbx-2.1.1, Asterisk 1.2.29 and Asterisk Addons 1.2.9
i tried to upgrade to Asterisk and Addons 1.4.7
all of the IAX trunks got not working at all.

I tried to downgrade by “make clean; make; make install” in Atserisk 1.2.29 directory.but “make” gives errors in the end.

How can i downgrade asterisk again and undo all changes i made.

and can Backup and Restore return all the previous asterisk configurations?



I faced similiar problems after upgrade 1.4x -> 1.6.
Before this I copied the complete asterisk folder and installed from scratch (including OS to get a clean environment). Then copied the saved folder and did some modifications since syntax changed slightly in some cases (but it gives you the error messages in CLI in such cases).
It worked fine.

So how can i downgrade again?
do you think that “Restore” module in freepbx can return all the previous asterisk configuration?

how can i uninstall Asterisk 1.4 completely to reinstall 1.2.29 again?