Problems with bind 9.2.4

[Volker Lieder]

Hello list,
i need to setup a bind-server for severeal domains and users.
The setup seems to be fine, but in my tests i have to wait up to 6 
seconds for an unauthorized answer
for a domain-question wit nslookup or dig.
Perhaps somebody can tell me how i can tune my bind 9.2.4 installation.
If the asked domain is cached, the answer comes after a few 
milliseconds.
My Server is connected via 100MBit to the internet, so i think thats 
not the problem.
My OS is FreeBSD 5.3. Perhaps someone has a hint for me.

Greets
Volker Lieder