Named server fails to respond

[etieseler at gmail.com]

Hello list,

I have been getting stumped with my current issue.  I have a BIND
(9.2.4) server running on Redhat EL3.0.  It works most of the time, but
every now and again it fails to handle DNS requests.  While this is
happening I issue the following command on the DNS server:

#dig -t ANY maps4.rapmls.com @127.0.01
;; global options:  printcmd
;; connection timed out; no servers could be reached

I check with netstat and port 53 is listening on both the loopback and
the IP address of the server for both UPD and TCP.

I have disabled iptables and even went as far as to remove it entirely,
and the behavior has not changed.

After a few minutes it starts to handle requests again.  I am stumped!
The load on the server is minimal, looking through the log files with
debug level 3 does not reveal anything obvious (What should I look
for?)  This is an internal DNS server that does recursion.  It recieves
no requests from the Internet.  I have setup DNS on another server but
would like to get this resolved.  Any thoughts?  I will be happy to
provide further information if needed.

Thanks in advance!
Eduard Tieseler