Unfortunately Detailed Logging did not show "gethostbyaddr failed"  on the
master server
I will ask the client to setup detailed logging on their system.
Now  I am thinking that client running NIS, NIS++ or DNS for their host name
resolution and it may be causing some errors. I will have to investigate
this.

>The problem is probably one of resolution - netbackup tends to use hostname
rather than >interface name and this can cause conflicts - and if the
clients use other DNS servers this >has caused problems in the past.

Original setup was exactly like that... Now I am thinking that it is name
resolution issue and nothing more. But what puzzles me, It is not consistent

>Oh and check both server and client can see the Master
 Yes no problem there, BTW In my setup Master is NBU media server and NBU
server

Anyway I have some things to check now.
Thank you for your help

Denis