DCOM n WMI related problem

Hi,
Iam using WMI in VC++.
When I connect to a remote machine using IWbemServices->ConnectServer(),it's
successful most of the times but causing trouble sometimes.
When it fails,its not giving any information about the cause of failure.
None of the specified return values could be observed.
I observed in System Log tht an error event is being generated everytime
this happens.
The event id is 10009,source DCOM,description : DCOM was unable to
communicate with the computer using any of the configured
protocols.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.

Can anyone help me to get it n solve my problem?
Thanks n regards,
Rayudu Kamma.
rayuduk@eiqnetworks.com