If you have experienced some difficulties with the ComboBox control when using RIA Services, take a look at this general guidance for ComboBox usage posted by Jeff Handley.
Here are a few scenarios we looked at:
- Async loading of ItemsSource with a SelectedItem/SelectedValue binding;
- Cascading drop-downs such as selecting Year - Make - Model for a car;
- Binding a ComboBox to a list of non-Entity types, such as an IEnumerable<string>.