Thanks for your post.
In addition to checking the permissions on the scheduled task, you may delete the old scheduled task and re-create a new noe? Will same issue occur?
There are several triggers for this behavior. It is known that certain third party applications will make changes to the security descriptors
Software packages that are a known cause for this behavior:
-Trend Micro InterScan 5.5
-IBM Universe/2 database software 10.x.
Also you have Veritas Backup running, please temporarily stop them for test purpose.
Hope this helps.
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