Backups failing. with status code 73..

All - I need your help in fixing backup issues on one of my unix client machine. Here are the details..Much appreciated for the quick response..

Client machine: solaris 10

              Netbackup Ver: NetBackup-Solaris10 7.1

Netbackup Server machine: solairs 10

              Netbackup Ver: NetBackup-Solaris10 7.6.0.2

Issue: Full/Incr backups are failing everyday..

1. I can telnet to master server.

telnet <Master_server> 1556
Trying x.x.x.x.
Connected to Master_server.
Escape character is '^]'.

2. Service is running...

 root 15176     1   0   Oct 03 ?           0:14 /usr/openv/netbackup/bin/bpcd -standalone

3. Can ping the master server..

ping Master_server
Master_server is alive

4. Detailed Status log file on backup console..

bpstart_notify failed (73)