Unable to register function 'soa_insert' from plugin 'bind_plugin'

[holykim]

I found the warnings in /var/log/ispconfig/ispconfig.log file. Can I ignore this warning if I disabled DNS service on this server? Can you please someone to advise what's the meaning of this warning?

ISPConfig 3.5.0.1 installed as a slave server and referred to the following tutorial "The Perfect Server - CentOS 6.4 x86_64 (Apache2, Dovecot, ISPConfig 3)"

28.03.2013-05:57 - DEBUG - Set Lock: /usr/local/ispconfig/server/temp/.ispconfig_lock
28.03.2013-05:57 - DEBUG - Unable to register function 'soa_insert' from plugin 'bind_plugin' for event 'dns_soa_insert'
28.03.2013-05:57 - DEBUG - Unable to register function 'soa_update' from plugin 'bind_plugin' for event 'dns_soa_update'
28.03.2013-05:57 - DEBUG - Unable to register function 'soa_delete' from plugin 'bind_plugin' for event 'dns_soa_delete'
28.03.2013-05:57 - DEBUG - Unable to register function 'slave_insert' from plugin 'bind_plugin' for event 'dns_slave_insert'
28.03.2013-05:57 - DEBUG - Unable to register function 'slave_update' from plugin 'bind_plugin' for event 'dns_slave_update'
28.03.2013-05:57 - DEBUG - Unable to register function 'slave_delete' from plugin 'bind_plugin' for event 'dns_slave_delete'
28.03.2013-05:57 - DEBUG - Unable to register function 'rr_insert' from plugin 'bind_plugin' for event 'dns_rr_insert'
28.03.2013-05:57 - DEBUG - Unable to register function 'rr_update' from plugin 'bind_plugin' for event 'dns_rr_update'
28.03.2013-05:57 - DEBUG - Unable to register function 'rr_delete' from plugin 'bind_plugin' for event 'dns_rr_delete'
28.03.2013-05:57 - DEBUG - Remove Lock: /usr/local/ispconfig/server/temp/.ispconfig_lock