DataGridView - Saving And Restoring Column Order?

Sometimes I select a value in my Combobox by hand, and sometimes the value to show is chosen elsewhere in my program logic. I want to carry out a certain action only when I have chosen a value by hand, and not when the value is changed by the program. For this reason I use the DropDownClosed event (and not, for example, SelectedValueChanged or SelectedIndexChanged). This works fine, but if I set AutoCompleteMode of my Combobox to Suggest, selecting a value from the suggested list doesn't fire the DropDownClosed event (perhaps logical, as the actual drop down list doesn't actually open).