SQL Express 2005 Backup Error

I am doing a backup of a SQL Express 2005 Database and am getting an error I do not understand:

10 percent processed. (Severity 0, state 1, error number 3211, line 1)
20 percent processed. (Severity 0, state 1, error number 3211, line 1)
30 percent processed. (Severity 0, state 1, error number 3211, line 1)
40 percent processed. (Severity 0, state 1, error number 3211, line 1)
50 percent processed. (Severity 0, state 1, error number 3211, line 1)
60 percent processed. (Severity 0, state 1, error number 3211, line 1)
70 percent processed. (Severity 0, state 1, error number 3211, line 1)
80 percent processed. (Severity 0, state 1, error number 3211, line 1)
90 percent processed. (Severity 0, state 1, error number 3211, line 1)
Processed 1024 pages for database 'DB_core', file 'Server' on file 1. (Severity 0, state 1, error number 4035, line 1)
100 percent processed. (Severity 0, state 1, error number 3211, line 1)
Processed 1 pages for database 'DB_core', file 'Server_log' on file 1. (Severity 0, state 1, error number 4035, line 1)
BACKUP DATABASE successfully processed 1025 pages in 0.677 seconds (12.397 MB/sec). (Severity 0, state 1, error number 3014, line 1)

Any advise?
thanks.