named process increasing dramatically

[Rinaldi Ariesta R]

today I notice that when i use the top command on my dns server (bind
8.2.2P5 under FreeBSD 3.4), my named process reach almost 80-90 % of CPU.

link to the internet is currently very low

the process increment cause very slow responses from the server on dns
queries

i haven't found anything meaningful or unusual from the log messages...

what could possibly happening on my server ?
  
  -orin-
Aroes Koeat