Funny named 8.2 behavior

[Pandit, Tushar]

I keep on again getting funny behavior from named 8.2. Yesterday named was not answering any queries. I 
did a 'netstat -a | grep bind' and found that named was stuck reading from uni00ns.unity.ncsu.edu. 
Command 'netstat -n' gave me the Recv-Q having a lot of data but the Send-Q was not reading it.
Today in the morning, I took a dump of the cache and the stats of my named using the foll. commands:

kill -INT `cat /var/run/named.pid`
kill -ILL `cat /var/run/named.pid`
kill -USR1 `cat /var/run/named.pid`.

And well, after that named started working and was answering queries. I am not sure what is going
out here. I also again did a netstat and it had the foll. o/p:
tsgops# netstat -a | grep bind
udp        0      0  tsgops-bind           *-*                   
udp        0      0  localhost-bind        *-*                   
udp        0      0  tsgops1-bind          *-*                   
tcp        0      0  tsgops-bind           *-*                   LISTEN
tcp        0      0  localhost-bind        *-*                   LISTEN
tcp        0      0  tsgops1-bind          *-*                   LISTEN

I don't know why giving the kill signal made it to work again ? And also the reason that why should named just
stop answering queries.

Any suggestions ? 

Thanks much.

Tushar