The backup is performed using an Execute T-SQL task. We wrote the code, tested it in SSMS and it performed without flaws. When the Backup task follows the long running DBCC, this is using an Execute T-SQL Task as well, the backup only executes for about 7-8 minutes and stops reporting success. When we run the code in each of the tasks separately it will complete without problems. The symptom is very strange, no errors, no messages other than success.
Thanks for your input.