i usually put the Me![cboname of box]= Null at the end of the combo box afterupdate event.

Sub Combobox_AfterUpdate()
' Find the record that matches the control.
Me.RecordsetClone.FindFirst "[record id] = " & Me![Combobox]
Me.Bookmark = Me.RecordsetClone.Bookmark
Me![Combobox] = Null

End Sub

works like a charm, you can even do it if access makes an embedded macro, just add this action.

have always wondered why they don't make that a default part of the code. must confuse a lot of people.