Hello Ernesto Morin,
You can check these articles for more information about the drag drop scenarios:
If these do not help, could you please send post some additional information about our scenario - code behind and XAML.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items