Hi Richard Koslik,
Do you use WCF Ria Services? If so, the new data will not be sent back to the server until you call the SubmitChanges() method of the DomainDataSource. So, if you do not submit the changes they are saved only in RadGridView. I think this is what you want.
Maybe your scenario is a bit different? In that case please open a support ticket and attach a sample project there so we can have a better idea of what is going on.
the Telerik team
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