diff --git a/eeschema/block.cpp b/eeschema/block.cpp
index ac84676903..443c3c96fa 100644
--- a/eeschema/block.cpp
+++ b/eeschema/block.cpp
@@ -478,7 +478,12 @@ void SCH_EDIT_FRAME::PasteListOfItems( wxDC* DC )
         destFn.MakeAbsolute( Prj().GetProjectPath() );
 
     // Make sure any sheets in the block to be pasted will not cause recursion in
-    // the destination sheet.
+    // the destination sheet. Moreover new sheets create new sheetpaths, and component
+    // alternante references must be created and cleared
+    bool hasSheetPasted = false;
+    // Keep trace of existing sheet paths. Paste block can modify this list
+    SCH_SHEET_LIST initial_sheetpathList( g_RootSheet );
+
     for( i = 0; i < m_blockItems.GetCount(); i++ )
     {
         item = (SCH_ITEM*) m_blockItems.GetItem( i );
@@ -512,6 +517,7 @@ void SCH_EDIT_FRAME::PasteListOfItems( wxDC* DC )
 
             sheet->SetName( wxString::Format( wxT( "sheet%8.8lX" ), (unsigned long)timeStamp ) );
             sheet->SetTimeStamp( timeStamp );
+            hasSheetPasted = true;
         }
     }
 
@@ -550,6 +556,14 @@ void SCH_EDIT_FRAME::PasteListOfItems( wxDC* DC )
 
     MoveItemsInList( picklist, GetScreen()->m_BlockLocate.GetMoveVector() );
 
+    if( hasSheetPasted )
+    {
+        // We clear annotation of new sheet paths.
+        // Annotation of new components added in current sheet is already cleared.
+        SCH_SCREENS screensList( g_RootSheet );
+        screensList.ClearAnnotationOfNewSheetPaths( initial_sheetpathList );
+    }
+
     // Clear flags for all items.
     GetScreen()->ClearDrawingState();
 
diff --git a/eeschema/operations_on_items_lists.cpp b/eeschema/operations_on_items_lists.cpp
index 8564059703..586504f10a 100644
--- a/eeschema/operations_on_items_lists.cpp
+++ b/eeschema/operations_on_items_lists.cpp
@@ -239,6 +239,11 @@ void DuplicateItemsInList( SCH_SCREEN* screen, PICKED_ITEMS_LIST& aItemsList,
     if( aItemsList.GetCount() == 0 )
         return;
 
+    // Keep trace of existing sheet paths. Duplicate block can modify this list
+    bool hasSheetCopied = false;
+    SCH_SHEET_LIST initial_sheetpathList( g_RootSheet );
+
+
     for( unsigned ii = 0; ii < aItemsList.GetCount(); ii++ )
     {
         newitem = DuplicateStruct( (SCH_ITEM*) aItemsList.GetPickedItem( ii ) );
@@ -270,6 +275,7 @@ void DuplicateItemsInList( SCH_SCREEN* screen, PICKED_ITEMS_LIST& aItemsList,
 
                 sheet->SetName( wxString::Format( wxT( "sheet%8.8lX" ), (unsigned long)timeStamp ) );
                 sheet->SetTimeStamp( timeStamp );
+                hasSheetCopied = true;
                 break;
             }
 
@@ -285,6 +291,14 @@ void DuplicateItemsInList( SCH_SCREEN* screen, PICKED_ITEMS_LIST& aItemsList,
     }
 
     MoveItemsInList( aItemsList, aMoveVector );
+
+    if( hasSheetCopied )
+    {
+        // We clear annotation of new sheet paths.
+        // Annotation of new components added in current sheet is already cleared.
+        SCH_SCREENS screensList( g_RootSheet );
+        screensList.ClearAnnotationOfNewSheetPaths( initial_sheetpathList );
+    }
 }
 
 
diff --git a/eeschema/sch_component.cpp b/eeschema/sch_component.cpp
index e23c34a4ac..8c09d18c2c 100644
--- a/eeschema/sch_component.cpp
+++ b/eeschema/sch_component.cpp
@@ -1124,10 +1124,10 @@ void SCH_COMPONENT::ClearAnnotation( SCH_SHEET_PATH* aSheetPath )
 }
 
 
-void SCH_COMPONENT::AddSheetPathReferenceEntry( const wxString& aSheetPathName )
+bool SCH_COMPONENT::AddSheetPathReferenceEntryIfMissing( const wxString& aSheetPathName )
 {
-    if( aSheetPathName.IsEmpty() )
-        return;
+    // a empty sheet path is illegal:
+    wxCHECK( !aSheetPathName.IsEmpty(), false );
 
     wxString reference_path;
 
@@ -1142,11 +1142,12 @@ void SCH_COMPONENT::AddSheetPathReferenceEntry( const wxString& aSheetPathName )
 
         // if aSheetPath is found, nothing to do:
         if( reference_path.Cmp( full_AR_path ) == 0 )
-            return;
+            return false;
     }
 
     // This entry does not exist: add it, with a (temporary?) reference (last ref used for display)
     AddHierarchicalReference( full_AR_path, m_Fields[REFERENCE].GetText(), m_unit );
+    return true;
 }
 
 
diff --git a/eeschema/sch_component.h b/eeschema/sch_component.h
index 1a0cc53dbf..ce57fac18d 100644
--- a/eeschema/sch_component.h
+++ b/eeschema/sch_component.h
@@ -304,8 +304,11 @@ public:
      * In component lists shared by more than one sheet path, an entry for each
      * sheet path must exist to manage references
      * @param aSheetPathName is the candidate sheet path name
+     * this sheet path is the sheet path of the sheet containing the component,
+     * not the full component sheet path
+     * @return false if the alternate reference was existing, true if added.
      */
-    void AddSheetPathReferenceEntry( const wxString& aSheetPathName );
+    bool AddSheetPathReferenceEntryIfMissing( const wxString& aSheetPathName );
 
     /**
      * Change the time stamp to \a aNewTimeStamp and updates the reference path.
diff --git a/eeschema/sch_screen.cpp b/eeschema/sch_screen.cpp
index 6e4c73c1d3..8d8146b624 100644
--- a/eeschema/sch_screen.cpp
+++ b/eeschema/sch_screen.cpp
@@ -734,8 +734,7 @@ void SCH_SCREEN::EnsureAlternateReferencesExist()
 
         // Add (when not existing) all sheet path entries
         for( unsigned int ii = 0; ii < m_clientSheetPathList.GetCount(); ii++ )
-            ((SCH_COMPONENT*)item)->AddSheetPathReferenceEntry( m_clientSheetPathList[ii] );
-
+            ((SCH_COMPONENT*)item)->AddSheetPathReferenceEntryIfMissing( m_clientSheetPathList[ii] );
     }
 }
 
@@ -1382,11 +1381,7 @@ void SCH_SCREENS::ClearAnnotationOfNewSheetPaths( SCH_SHEET_LIST& aInitialSheetP
         {
             // A new sheet path is found: clear the annotation corresponding to this new path:
             SCH_SCREEN* curr_screen = sheetpath.LastScreen();
-            #if 0   // For test and debug only
-            wxLogMessage(">>>new path %s <%s> screen %p usage %d",
-                sheetpath.Path(), sheetpath.PathHumanReadable(),
-                curr_screen, curr_screen->GetClientSheetPathsCount() );
-            #endif
+
             // Clear annotation and create the AR for this path, if not exists,
             // when the screen is shared by sheet paths.
             // Otherwise ClearAnnotation do nothing, because the F1 field is used as