For Ubuntu 6.x and higher.

For if your hfaxd daemon is acting funny (client gives "can't get a socket" errors).

Edit your event.d file for your modem:

sudo vi /etc/event.d/ttyS0

If it is empty, first do the last instructions in the Handbook for Binary Package Install

http://www.hylafax.org/content/Handbook:Binary_Package_Install

Then add this line to the end and save:

exec /init.d/hylafax