I am using the example found at (http://www.telerik.com/help/silverlight/raddraganddrop-within-radgridview.html) to add drag and drop capabilitiy for RadGridView rows within the RadGridView itself. One problem that I ran into is that the provided example will effectively insert space above the RadGridView itself, but you will not notice this until you set the ShowGroupPanel to False. The easiest fix that I found was to add the following line of code to the end of the RowReorderBehavior constructor (in RowReorderBehavior.cs):
Grid.SetRow(
this
.dropPositionFeedbackPresenter, 2);