Asterisk should have a use dependency for Zaptel in the startup scripts so that any Zaptel hardware can be initialized before asterisk is started. Alternately, Zaptel could have a before dependency to asterisk. Either way should ensure that Asterisk starts cleanly when configured to use Zaptel hardware.
asterisk has depend() { need net logger after zaptel } in /etc/init.d/asterisk
My fault. I see that this is fixed in 1.0.7-r1 which is not yet marked ~x86.