Minor There is no error message printed to syslog if the hidden master uses tsig for the notify and you have no tsig configured. But you will see the error if you run in verbose mode.
Nov 29 14:05:48 ubuntu named[30052]: received control channel command 'reload bellgrim.se'
Nov 29 14:05:48 ubuntu named[30052]: zone bellgrim.se/IN: loaded serial 2011032118
Nov 29 14:05:48 ubuntu named[30052]: zone bellgrim.se/IN: sending notifies (serial 2011032118)
Nov 29 14:05:48 ubuntu ods-signerd: [socket] incoming udp message
Nov 29 14:05:48 ubuntu ods-signerd: [query] tsig ok
Nov 29 14:05:48 ubuntu ods-signerd: [query] incoming notify for zone bellgrim.se
Nov 29 14:05:48 ubuntu ods-signerd: [acl] no match: tsig present but no config
Nov 29 14:05:48 ubuntu ods-signerd: [acl] no match
Nov 29 14:05:48 ubuntu ods-signerd: [query] refused
Nov 29 14:05:48 ubuntu ods-signerd: [socket] sending 165 bytes over udp
Nov 29 14:05:48 ubuntu ods-signerd: [dnshandler] netio dispatch