Rc.filter_synchronize not running automatically

[nothing]

Hi,
I have two nodes with pfsense 2.1. I've noticed the configuration was not syncing since few weeks. And I have no messages/errors in the syslog mentioning xmlrpc.
The last message with xmlrpc is 1 month ago - authentication failure. I was changing the passwords that time, so it's OK. And it suddenly stops syncing.
I can run manually /etc/rc.filter_synchronize and it syncs successfully, but it's not doing it automatically after I commit change on the master node.

Any ideas what I can check to solve this? I've already tried restarting both nodes - no result.

[nothing]

Maybe that's some clue:

[2.1-RELEASE][admin@master]/root(1): check_reload_status
/libexec/ld-elf.so.1: Shared object "libevent-1.4.so.4" not found, required by "check_reload_status"

Maybe a package I've installed and uninstalled have deleted this library, it's really missing on the master node.
But it's there on the slave:

[2.1-RELEASE][admin@slave]/root(2): find / -name libevent-1.4.so.4
/usr/local/lib/libevent-1.4.so.4

[nothing]

Well, it seems this saved the day:

[2.1-RELEASE][admin@master]/root(20): pkg_add -r http://files.pfsense.org/packages/amd64/8/All/libevent-1.4.14b_2.tbz

Definitely this is bug.