did you import the data before you provisioned or after you provisioned the new syncgroup? what tool did you use to import the Access DB?
if you imported the data after you provisioned and the tool you use to import uses bulk copy type of operations that dont fire triggers, the tracking tables are not populated, so no changes are detected.
try removing the sync group and recreating it.
btw, if you want to clean up the sync related objects from the copy of your database, you can run the deprovisioning utility located in the same folder you installed the data sync agent.