This happens only with editable ComboBox in Silverlight.

When the ItemsSource for a RadComboBox is bound to a collection with two different properties, id and ID.  When I bind SelectedValuePath to one of the properties, changing selection throw error:  "Ambiguous match found" exception.

When moving through elements(checkbox+ text) in RadCombobox with the keyboard, focus of combobox is not changed as expected.
Sample project attached.