ExampleDragDropItem script instantiates the prefab using NGUITools.AddChild (line 29 of ExampleDragDropItem.cs). AddChild resets the scale to (1, 1, 1). If you want the scale to be the same as it is in the prefab, add this line right after:Note that this is an Example script. It's meant to be modified to suit your needs.
child.transform.localScale = dds.transform.localScale;
Replace "NGUITools.AddChild" with a simple "(GameObject)Instantiate". Check Unity's documentation on Instantiate: http://docs.unity3d.com/Documentation/ScriptReference/Object.Instantiate.html