ObjectContainerDatasource onselecting called twice

Question

Hi guys, This is my first attempt to work with WCSF and MVP here is the setup. a search button when clicked it fires an event to get the data from service

public void OnSelecting(int startRowIndex, int maximumRows, string sortExpression) {

            View.Persons = Controller.GetPersons(startRowIndex, maximumRows, sortExpression, View.PersonId);
             View.TotalPersonsCount =Controller.PersonsTotalCount;

    }

public IList Persons {

        set {
            PersonDataSource.DataSource = value;

            }

    }

when this method is called, it returns the data Ok but the ObjectContainerDatasource also calls its OnSelecting event I have a gridview bound to an ObjectContainerDatasource any idea how to correct this behavior?

Thanks