When you follow te 'offical' How-To, it should work perfectly...
There are many different update to the individual packages, but stick to a complete working package and freeze it, so you can fax! An update of some package doesn't mean you (or your users) can benefit from it.
If you follow the How-To you can replac the Beta version Hylafax with the currecnt official release. The only different for you will be that at some point it will refer to /var/spool/fax and for the currecnt release for Hylafax it will be /var/spool/hylafax
HFW