Copy paste in UML Packages

[Nicolas Hohm <nickel7152 gmail com>]

Hey guys,
i'm using DIA for creating a uml class diagramm. Now i have created a diagramm and like to create packages. 
How can i move existing classes into a package or using copy&paste to duplicate classes created in the 
package?

The problem is if I move a class into a package the class will not become a child of the package, but if i 
create a new class and click in the pacakge frame the class is a child of the package.