Thanks for the reply. You are doing very good for HP Data Protector community. Helping alot other members in time of need :-)
Ok now as far as concerned with my issues I am trying to apply 7.03 patches to check if it resolve issue or else I will open a case with HP.
Also would like to bring into your notice one more thing that for this same backup if my (VSS) "volume shadow services" is disabled the backup fails staright away with errors no mount point availaible and if I start VSS services backup goes fine with above mentioned error.
But the problem here is "Volume shadow services" for this client is getting disabled automatically after 5-8mins. In the event log of server it only shows event 7036 ...information VSS services get disabled.