Auto refresh cached nameservers

I'm running into an interesting problem with my bind 9.2.1
installation. I recently updated the list of authoritative nameservers
for my domain (at netsol.com). Unfortunately, all of the servers I
have bind running on do not pick up this change until I restart the
named process.

Until I restart the process, they continue using the original
nameservers, and return the IP addresses that those older nameservers
have. After a restart of the process, they immediately recognize the
new nameservers and return the IP's given by those new nameservers.
Even weirder, when doing a 'dig' on the domain name, it uses the the
older nameservers. However, if I do a 'dig +trace' it uses the new
nameservers.

My impression is that it has the original set of nameservers cached
and continues to use the cache indefinitely. When doing a 'dig +trace'
it doesn't use that cache, and as a result see's the new set of
nameserver after contacting the root dns servers.

My question is this...is there any setting or option I can configure
to have it refresh its cached list of nameservers automatically, or
will I be forced to have a cronjob that restarts the nameservers every
so often? Seems like a pretty nasty bug/feature.


Any help would be appreciated,
Lenny