I've never seen logs like that before - are they in messages or syslog?
There was a recent TechAlert dealing with upcoming credential expiry for NBAC users who installed NBAC many years ago - I wonder if what you're seeing is part of that?
Look here:
NETBACKUP ADVISORY: If the self-signed certificate generated by the root broker is not updated before its expiry date - potentially eight years from its generation - any credentials issued from its associated authentication brokers may become untrustworthy and unusable because the root signing authority is no longer valid.
http://support.veritas.com/docs/345042
The `vssat showalltrustedcreds` should show if you have something expiring in June...
If this IS the case, there is a certificate updater you can download and use with 6.5.4 to renew the certificate here:
DOCUMENTATION: Usage and syntax of the NetBackup Certificate Update Utility (nbcertupdater).
http://support.veritas.com/docs/345043
This is only a guess - I really am not sure what your log message means without more context. Good luck! (Bonne chance! :) )