I put my thinking head on and came up with the following reason for this seemingly odd behaviour. Comboboxes (and Listboxes) maintain two collections. One is the Items collection, the other a collection of strings that will be displayed by the list box part of the control. When you insert (or add) an object two things happen. First a reference to the object is placed in the Items collection. Secondly, the object's ToString() method is called and the result placed in the hidden strings collection. This is what is displayed in the list. With the code I used the d = New TheData() creates five objects on the heap and references to these objects are placed in Items collection. When the d = New TheData() lines are commented out, only one object is created on the heap (when d is Dimmed). So all of the references in Items collection point to the same object. This object will have the values last inserted into the list. The selection methods of the combobox operate on the Items collection so they will return what appears to be the last item inserted for all positions. Because of the two collections, the displayed list can be quite different to what is actually in the Items collection. In the SelectedItemsChanged handler you could update the fields in the item, e.g. by setting secondString to "Impossible", but this would not change the displayed list. As far as I'm aware you cannot get direct access to the strings collection. The Combobox control maintains this collection when you add, insert or remove items. Note that the Listbox control behaves in exactly the same way. Regards David Rice
