So, this article should help you track down the tasks:
"How can I find out if a Resource still exists in the Console, just in case it is hidden?"
http://www.symantec.com/docs/HOWTO6526
You could maybe then delete them using this:
"How to delete an item using the ASDK tools?"
On the SMP Server run:
AltirisASDKNS.exe cmd:DeleteItem "ItemGuid:7933a506-e412-4115-a857-3c66e5485628"
from %Program Files%\Altiris\Altiris ASDK\Bin in a command prompt as the Application Identity account
http://www.symantec.com/docs/HOWTO101657