Slave/secondary DSN does not respond unless server command used in NSlookup

[ali at astpower.com]

Hello Everyone,

I have a Master  and Slave  DNS.  They work fine, and all file gets copied to Slave DNS when I start named.
I define both Master and Slave DNS(s) in the Windows 2000 and everything was working
Now ---- 
I stop the named in the Master DNS and the Salve DNS was able to resolve all names.

But when I went to the  Windows 2000  and execute  Nslookup, it stop to work, and it only works when I start the named in the Master DSN server.

Results of Windows 2000 nslookup :

C:\Documents and Settings\Administrator>nslookup ptree.mydom.com
*** Can't find server name for address 192.168.33.19: No response from server
*** Can't find server name for address 192.168.33.42: Non-existent domain
*** Default servers are not available
Server:  UnKnown
Address:  192.168.33.19

*** UnKnown can't find ptree: No response from server 

NOW!  in Windows 2000, when I try nslookup again but with  pointing manually to the Slave DNS it can resolve the hosts


> server 192.168.33.42
Default Server:  [192.168.33.42]
Address:  192.168.33.42

> ptree.uniworld.com
Server:  [192.168.33.42]
Address:  192.168.33.42

Name:    ptree.uniworld.com
Address:  192.168.33.165


Can any please tell me what is wrong with my Slave DNS configuration?

Thanks
Ali