netbackup asa db issue

I am seeing below error messages

02/12/2014 00:03:36 xxxxxx -  Error cleaning up the DBM_ImageChangeLog records
                    in NBDB.
02/12/2014 06:14:16 xxxxxx-  Error cleaning up the DBM_ImageChangeLog records
                    in NBDB.
02/12/2014 10:12:59 xxxxxx -  Error cleaning up the DBM_ImageChangeLog records
                    in NBDB.
 

xxxxx is master serevr hostname

also, nbdb.log file is about 2.3 GB

-rw-------   1 root     root     2515795968 Feb 12 12:31 NBDB.log

are these errors of concern, we are going for upgrade  from

VERSION:  7.0,REV=2010.01.06.21.06
   BASEDIR:  /opt
    VENDOR:  Symantec Corporation
 

to  7.5