Combobox displaymember value reset

Hi

I am trying to set the Datsouce/DisplayMember/ValueMember properties at runtime from a collection object that inherits from CollectionBase. I am observing that the DisplayMember is being reset to the Valuemember value. any thoughts I have tried moving the lines of code that sets these properties around but there is no change in behavior.

private void Form_Load()

{

InitializeData();

}

private void InitializeData()

{

dropdownlistEmployee.DataSource = EmployeeListObject;

dropdownlistEmployee.DisplayMember = "Login";

dropdownlistEmployee.ValueMember = "EmployeeID";

}