Hi!
Unfortunately, firebird is somehow broken on Ubuntu. You get the hint on what's wrong from the following line:

> find: `/var/run/firebird/2.1': No such file or directory

To work around this problem, make sure that this directory is there. Something in Ubuntu deletes it on every reboot, so i added this to my /etc/init.d/bootmisc.sh:
mkdir -p /var/run/firebird/2.1
chown -R firebird:firebird /var/run/firebird
chmod -R 770 /var/run/firebird

hth,
Michael