diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index ca548e1aa..f83ba8a60 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -774,18 +774,20 @@ sub split_object {
     my ($obj_idx, $current_object)  = $self->selected_object;
     
     # we clone model object because split_object() adds the split volumes
-    # into the same model object, thus causing duplicated when we call load_model_objects()
-    my $current_model_object        = $self->{model}->clone->objects->[$obj_idx];
+    # into the same model object, thus causing duplicates when we call load_model_objects()
+    my $new_model = $self->{model}->clone;  # store this before calling get_object()
+    my $current_model_object = $new_model->get_object($obj_idx);
     
-    if (@{$current_model_object->volumes} > 1) {
+    if ($current_model_object->volumes_count > 1) {
         Slic3r::GUI::warning_catcher($self)->("The selected object can't be split because it contains more than one volume/material.");
         return;
     }
     
-    $self->stop_background_process;
+    $self->pause_background_process;
     
     my @model_objects = @{$current_model_object->split_object};
     if (@model_objects == 1) {
+        $self->resume_background_process;
         Slic3r::GUI::warning_catcher($self)->("The selected object couldn't be split because it contains only one part.");
         return;
     }
diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index 06919cedd..40926eb93 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -13,7 +13,7 @@ Model::Model(const Model &other)
     // copy objects
     this->objects.reserve(other.objects.size());
     for (ModelObjectPtrs::const_iterator i = other.objects.begin(); i != other.objects.end(); ++i)
-        this->add_object(**i);
+        this->add_object(**i, true);
 }
 
 Model& Model::operator= (Model other)
@@ -618,6 +618,7 @@ ModelObject::split(ModelObjectPtrs* new_objects)
         new_volume->material_id(volume->material_id());
         
         new_objects->push_back(new_object);
+        delete *mesh;
     }
     
     return;
diff --git a/xs/src/perlglue.hpp b/xs/src/perlglue.hpp
index 833eee6f3..84c9a7ae9 100644
--- a/xs/src/perlglue.hpp
+++ b/xs/src/perlglue.hpp
@@ -42,9 +42,9 @@ template <class T>
 class Ref {
     T* val;
 public:
-    Ref() {}
+    Ref() : val(NULL) {}
     Ref(T* t) : val(t) {}
-    operator T*() const {return val; }
+    operator T*() const { return val; }
     static const char* CLASS() { return ClassTraits<T>::name_ref; }
 };
   
@@ -52,10 +52,10 @@ template <class T>
 class Clone {
     T* val;
 public:
-    Clone() : val() {}
+    Clone() : val(NULL) {}
     Clone(T* t) : val(new T(*t)) {}
     Clone(const T& t) : val(new T(t)) {}
-    operator T*() const {return val; }
+    operator T*() const { return val; }
     static const char* CLASS() { return ClassTraits<T>::name; }
 };
 };