BIND9 Latency

[Tom Smith]

My setup: Ubuntu 6.06, BIND 9, VMware Server (all on the most recent 
versions). The DNS server is operating with in a VMware Server Virtual 
Machine.

The DNS server is set up as a master for the office in which it resides, 
with the Corporate office server as a slave for that office's domain. 
The is also a master-slave relationship from Corporate to this remote 
office. Otherwise, it functions as a caching name server.

The problem is that it seems to time out quite frequently when resolving 
non-local domain names--that is, it times out when resolving Internet 
domain name... It always works when resolving internal names. The only 
way I've found, so far, to resolve this is to restart the bind9 service.

There are no errors in any of the logs (that I can find) and there don't 
appear to be any other anomalies occurring when the problem crops up.

Can anyone offer any suggestions as to what might be going on or ways of 
tracking down this problem?

Thanks in advance for your help!

~ Tom