BIND 9.5 Stopped listening on SUN Solaris 10

[TCPWave Customer Care]

Hi BIND Users,

In one of our customer sites, the DNS process was found running on
multiple cache serversbut is was not responding to a dig @localhost.

The named version is BIND 9.5.1-P2 with security fixes from BIND
9.5.2-P3.

The named process was in a hung state. The recursive cache could not
communicate  with the roots. Therefore the queries were timing out
causing a wide spread outage. 

Restarting the DNS process resolved the problem. The servers had an
uptime of over 300 days.

There are no significant lines in the /var/adm/messages or in named.log
to pinpoint the problem.

Could this version have anything to do with the recent BIND bug that was
fixed via BIND 9.7.3-P3?

Did our customer hit a known bug?

Any help regarding this will be appreciated.

general: info: sockmgt 1006e49b0: maximum number of FD events (64)
received lines are seen in the logs.

Thanks
Sam.