What version of bind are you running? Here you get some hints: http://www.freebsddiary.org/bind-version.php

quick hack:

$ nslookup -q=txt -class=CHAOS version.bind. 0
Server: ducky.nz.freebsd.org
Address: 0.0.0.0 
VERSION.BIND text = "8.2.2-P5"

Force transfer of given zone:

rndc reload zone  

Remove a given name out of your cache:

rndc flushname your.host.tld