You can look into the client machines (\Documents and settings\All users\Application data\McAfee\Common framework).
Under Tasks folder, there will be couple of ini files. Plesae open them and verify if the ODS scan task is created or not.
If you want to see whether task has run or not. If you can verify it locally from VSE console=>Full scan=>View logs. That will show the date/time when its ran.
If you want to query from ePO server then please run a query against Event ID: 1202 and 1203.
Event ID: 1202 is for On-demand scan started and ID 1203 is for On Demand scan complete.