Standard query response, Server failure?

[Jiann-Ming Su]

Running 9.2.2 on several old RedHat 7.3 systems.  Some users were
noticing slow responses from one particular nameserver.  When I trace
the traffic, I see "Server failure" in response to a "query A."  What
level of debugging can I run to collect more info?  And, what would
cause such an error?  The other nameservers don't see to have this
same problem.  Thanks for any tips.

-- 
Jiann-Ming Su
"I have to decide between two equally frightening options.
 If I wanted to do that, I'd vote." --Duckman
"The system's broke, Hank.  The election baby has peed in
the bath water.  You got to throw 'em both out."  --Dale Gribble
"Those who vote decide nothing.
Those who count the votes decide everything."  --Joseph Stalin