Server not responding to queries

[Lokesh K]

On Bind 9.2, with notify and notify-also enabled on master server and
with heavy updates on zones, I am observing that slaves stop responding
to queries after some time. The error message on slave is,
"Transport of 'testzone.com/IN' from <IPAddress>#53: failed while
receiving responses: connection reset"
After this error message there is no response for any queries from
slaves. After restarting the server, it works fine. 
 
It looks like it's because of the salve servers not able to handle the
updates. Is there any I can reduce the number of notify messages sent
from master or any other configuration to avoid this problem?
 
Thanks in advance,
Lokesh