Duplicate works!

Instance.cpp

@@ -16,9 +16,9 @@ Instance::Instance(void)
 
 Instance::Instance(const Instance &oinst)
 {
-	parent = oinst.parent;
+	setParent(oinst.parent);
 	name = oinst.name;
-	className = "BaseInstance";
+	className = oinst.className;
 }
 
 void Instance::render(RenderDevice* rd)

Instance.h

@@ -18,7 +18,7 @@ public:
 	void addChild(Instance*);
 	void removeChild(Instance*);
 	Instance* getParent();
-	Instance* clone() const { return new Instance(*this); }
+	virtual Instance* clone() const { return new Instance(*this); }
 protected:
 	std::string className;
 	Instance* parent;  // Another pointer.

PhysicalInstance.cpp

@@ -28,7 +28,7 @@ PhysicalInstance::PhysicalInstance(const PhysicalInstance &oinst)
 	name = oinst.name;
 	className = "Part";
 	canCollide = oinst.canCollide;
-	
+	setParent(oinst.parent);
 	anchored = oinst.anchored;
 	size = oinst.size;
 	setCFrame(oinst.cFrame);

main.cpp

@@ -252,9 +252,7 @@ void GUDButtonListener::onButton1MouseClick(BaseButtonInstance* button)
 			std::vector<Instance*> newinst;
 			for(size_t i = 0; i < selectedInstances.size(); i++)
 			{
-				Instance* inst = selectedInstances.at(i)->clone();
-				newinst.push_back(inst);
-				inst->setParent(selectedInstances.at(i)->getParent());
+				newinst.push_back(selectedInstances.at(i)->clone());
 			}
 			selectedInstances = newinst;
 		}