DECLINED: This is a limitation of the DataSet model. The last section "Updating the database" of this help article http://www.telerik.com/help/winforms/scheduler-data-binding-data-binding-walkthrough.html explains how you can overcome this.

Steps to reproduce:
1. Bind RadScheduler to a database with appointments and resources.
2. Add a few appointments, save and close the form.
3. Delete the last added appointment, save and close the form.
4. When you add a new appointment and try to save, an SQL exception will be thrown.