Now that mediatomb uses upstart, the problem is that NO_START is not used anymore... I had to change the /etc/init/mediatomb file so the NO_START value is checked just after sourcing the /etc/default/mediatomb file:
... script [ -r $DEFAULT ] && . $DEFAULT [ $NO_START = yes ] && exit 0 ...
Now that mediatomb uses upstart, the problem is that NO_START is not used anymore... I had to change the /etc/init/mediatomb file so the NO_START value is checked just after sourcing the /etc/default/ mediatomb file:
...
script
[ -r $DEFAULT ] && . $DEFAULT
[ $NO_START = yes ] && exit 0
...