I found that Webmin also has an interface for cron jobs:
http://localhost:9001/cron/
After deleting/updating the conf files, I re-ran the
install-a2billing script. I then deleted the any duplicated cron jobs using webmin.
However, as the script was running, I got the following error after I entered mySQL password:
ERROR 1062 (23000) at line 19: Duplicate entry '246' for key 1
I am not sure what that means.
I also got:
mv: cannot move `libs_a2billing' to a subdirectory of itself, `/var/lib/asterisk/agi-bin/libs_a2billing'
mv: cannot move `/usr/src/a2billing/addons/sounds/br' to a subdirectory of itself, `/var/lib/asterisk/sounds/br'
mv: cannot move `/usr/src/a2billing/addons/sounds/en' to a subdirectory of itself, `/var/lib/asterisk/sounds/en'
mv: cannot move `/usr/src/a2billing/addons/sounds/es' to a subdirectory of itself, `/var/lib/asterisk/sounds/es'
mv: cannot move `/usr/src/a2billing/addons/sounds/fr' to a subdirectory of itself, `/var/lib/asterisk/sounds/fr'
mv: cannot move `/usr/src/a2billing/addons/sounds/g729' to a subdirectory of itself, `/var/lib/asterisk/sounds/g729'
mkdir: cannot create directory `/var/lib/asterisk/a2billing/': File exists