If I understand this correctly, the Resource field saved as part of a TTMSFNCPlanner item is based on the position of the resource in the list. So the first resource in the list is 0. Is that correct?
In my case the resources are users, so I have added the resources in alphabetical order. If another user is added, wouldn't that mean that the previously saved resources/positions would now be incorrect?
Assuming you use TTMSFNCPlannerDatabaseAdapter, unless you implement TTMSFNCPlannerDatabaseAdapter.OnFieldsToResource / TTMSFNCPlannerDatabaseAdapter.OnResourceToFields , the position value equals the resource field value. With the events you can customize this mapping.