diff --git a/pcbnew/router/pns_item.h b/pcbnew/router/pns_item.h
index eac581437f..8fefbe94ea 100644
--- a/pcbnew/router/pns_item.h
+++ b/pcbnew/router/pns_item.h
@@ -53,7 +53,7 @@ public:
     PNS_OBJECT():
         m_owner( NULL ) {}
 
-    ~PNS_OBJECT() {};
+    virtual ~PNS_OBJECT() {}
 
     /**
      * Functon SetOwner()
diff --git a/pcbnew/router/pns_itemset.cpp b/pcbnew/router/pns_itemset.cpp
index 65ce45a7b0..e31ad8ae68 100644
--- a/pcbnew/router/pns_itemset.cpp
+++ b/pcbnew/router/pns_itemset.cpp
@@ -71,7 +71,14 @@ PNS_ITEMSET& PNS_ITEMSET::FilterLayers( int aStart, int aEnd, bool aInvert )
     BOOST_FOREACH( PNS_ITEM* item, m_items )
 
     if( item->Layers().Overlaps( l ) ^ aInvert )
+    {
         newItems.push_back( item );
+    }
+    else
+    {
+        if( item->BelongsTo( this ) )
+            item->SetOwner( NULL );
+    }
 
     m_items = newItems;
 
@@ -86,7 +93,14 @@ PNS_ITEMSET& PNS_ITEMSET::FilterKinds( int aKindMask, bool aInvert )
     BOOST_FOREACH( PNS_ITEM* item, m_items )
     {
         if( item->OfKind( aKindMask ) ^ aInvert )
+        {
             newItems.push_back( item );
+        }
+        else
+        {
+            if( item->BelongsTo( this ) )
+                item->SetOwner( NULL );
+        }
     }
 
     m_items = newItems;
@@ -102,7 +116,14 @@ PNS_ITEMSET& PNS_ITEMSET::FilterMarker( int aMarker, bool aInvert )
     BOOST_FOREACH( PNS_ITEM* item, m_items )
     {
         if( item->Marker() & aMarker )
+        {
             newItems.push_back( item );
+        }
+        else
+        {
+            if( item->BelongsTo( this ) )
+                item->SetOwner( NULL );
+        }
     }
 
     m_items = newItems;
@@ -118,7 +139,14 @@ PNS_ITEMSET& PNS_ITEMSET::FilterNet( int aNet, bool aInvert )
     BOOST_FOREACH( PNS_ITEM* item, m_items )
     {
         if( ( item->Net() == aNet ) ^ aInvert )
+        {
             newItems.push_back( item );
+        }
+        else
+        {
+            if( item->BelongsTo( this ) )
+                item->SetOwner( NULL );
+        }
     }
 
     m_items = newItems;
@@ -133,8 +161,15 @@ PNS_ITEMSET& PNS_ITEMSET::ExcludeItem( const PNS_ITEM* aItem )
 
     BOOST_FOREACH( PNS_ITEM* item, m_items )
     {
-        if( item != aItem )
-            newItems.push_back( item );
+        if( item == aItem )
+        {
+            if( item->BelongsTo( this ) )
+                item->SetOwner( NULL );
+
+            break;
+        }
+
+        newItems.push_back( item );
     }
 
     m_items = newItems;
diff --git a/pcbnew/router/pns_line.cpp b/pcbnew/router/pns_line.cpp
index f6f7ec3043..80c175ebfe 100644
--- a/pcbnew/router/pns_line.cpp
+++ b/pcbnew/router/pns_line.cpp
@@ -41,7 +41,7 @@ PNS_LINE::PNS_LINE( const PNS_LINE& aOther ) :
     m_net = aOther.m_net;
     m_movable = aOther.m_movable;
     m_layers = aOther.m_layers;
-    m_owner = NULL;
+    m_owner = aOther.m_owner;
     m_via = aOther.m_via;
     m_hasVia = aOther.m_hasVia;
     m_marker = aOther.m_marker;
@@ -146,7 +146,7 @@ PNS_SEGMENT* PNS_SEGMENT::Clone() const
     s->m_layers = m_layers;
     s->m_marker = m_marker;
     s->m_rank = m_rank;
-    s->m_owner = m_owner;
+    s->m_owner = NULL;
 
     return s;
 }