So, I've setup pfsense 1.2 using carp for automatic failover. This is very nice stuff! However, the ntpd server does not allow the ntpd server to be started on the LAN carp device. don't forget, that if you edit your openNTP settings, these changes will be lost. So…
Try this:
diagnostics->edit and load the following file:
/var/etc/ntpd.conf
and add the following line and save:
listen on 172.16.1.1 ( or whatever your LAN carp ip is )
diagnostics->command:
kill -KILL pgrep -u root ntpd && /usr/local/sbin/ntpd -f /var/etc/ntpd.conf