Error when using DCDIAG utility

Dear All,

I am running Windows 2000 Domain with a Parent and 2 Child Domains.

On Parent Domain when i run DCDIAG /e /test:frssysvol

then all the test are passed in one child domain but i got error on all  server which are part of other child domain. i.e

 Testing server: Sitename\servername
      Starting test: frssysvol
         [Servername] An net use or LsaPolicy operation failed with error 53, The
network path was not found..
         ......................... Servername failed test frssysvol


Now if I run same command on the server which is a part of defective child domain then i donot get this error and all the servers in that child domain sucessfully passed the test.

Please note that  all the server in defective child domain are accessible from Parent domain and a firewall is also placed in between Parent and Child domains.  

Please tell me where is the problem and how to fix it.

Thanks and Regards
Rehan