diff --git a/common/class_undoredo_container.cpp b/common/class_undoredo_container.cpp
index 2dd862ef01..9c71d1ad2d 100644
--- a/common/class_undoredo_container.cpp
+++ b/common/class_undoredo_container.cpp
@@ -343,7 +343,6 @@ PICKED_ITEMS_LIST* UNDO_REDO_CONTAINER::PopCommand()
         m_CommandsList.pop_back();
         return item;
     }
+
     return NULL;
 }
-
-
diff --git a/pcbnew/board_undo_redo.cpp b/pcbnew/board_undo_redo.cpp
index 8e0a6290c9..dd221f74d5 100644
--- a/pcbnew/board_undo_redo.cpp
+++ b/pcbnew/board_undo_redo.cpp
@@ -635,6 +635,9 @@ void PCB_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList, bool aRed
 
 void PCB_EDIT_FRAME::RestoreCopyFromUndoList( wxCommandEvent& aEvent )
 {
+    if( UndoRedoBlocked() )
+        return;
+
     if( GetScreen()->GetUndoCommandCount() <= 0 )
         return;
 
@@ -644,6 +647,7 @@ void PCB_EDIT_FRAME::RestoreCopyFromUndoList( wxCommandEvent& aEvent )
 
     /* Get the old list */
     PICKED_ITEMS_LIST* List = GetScreen()->PopCommandFromUndoList();
+
     /* Undo the command */
     PutDataInPreviousState( List, false );
 
@@ -658,6 +662,9 @@ void PCB_EDIT_FRAME::RestoreCopyFromUndoList( wxCommandEvent& aEvent )
 
 void PCB_EDIT_FRAME::RestoreCopyFromRedoList( wxCommandEvent& aEvent )
 {
+    if( UndoRedoBlocked() )
+        return;
+
     if( GetScreen()->GetRedoCommandCount() == 0 )
         return;
 
diff --git a/pcbnew/modedit_undo_redo.cpp b/pcbnew/modedit_undo_redo.cpp
index 2aa62c2134..ac72fd672f 100644
--- a/pcbnew/modedit_undo_redo.cpp
+++ b/pcbnew/modedit_undo_redo.cpp
@@ -129,6 +129,9 @@ void FOOTPRINT_EDIT_FRAME::RestoreCopyFromRedoList( wxCommandEvent& aEvent )
 
 void FOOTPRINT_EDIT_FRAME::RestoreCopyFromUndoList( wxCommandEvent& aEvent )
 {
+    if( UndoRedoBlocked() )
+        return;
+
     if( GetScreen()->GetUndoCommandCount() <= 0 )
         return;
 
@@ -136,6 +139,9 @@ void FOOTPRINT_EDIT_FRAME::RestoreCopyFromUndoList( wxCommandEvent& aEvent )
     TOOL_EVENT event( TC_MESSAGE, TA_UNDO_REDO, AS_GLOBAL );
     m_toolManager->ProcessEvent( event );
 
+    if( UndoRedoBlocked() )
+        return;
+
     // Save current module state in redo list
     PICKED_ITEMS_LIST* lastcmd = new PICKED_ITEMS_LIST();
     MODULE* module = GetBoard()->m_Modules.PopFront();
diff --git a/pcbnew/pcb_base_edit_frame.h b/pcbnew/pcb_base_edit_frame.h
index 4ad0de4385..3bb6cdec4e 100644
--- a/pcbnew/pcb_base_edit_frame.h
+++ b/pcbnew/pcb_base_edit_frame.h
@@ -37,7 +37,7 @@ public:
                 const wxString& aTitle, const wxPoint& aPos, const wxSize& aSize,
                 long aStyle, const wxString& aFrameName ) :
     PCB_BASE_FRAME( aKiway, aParent, aFrameType, aTitle, aPos, aSize, aStyle, aFrameName ),
-    m_rotationAngle( 900 )
+    m_rotationAngle( 900 ), m_undoRedoBlocked( false )
     {}
 
     virtual ~PCB_BASE_EDIT_FRAME() {};
@@ -71,10 +71,31 @@ public:
 
     bool PostCommandMenuEvent( int evt_type );
 
+    /**
+     * Function UndoRedoBlocked
+     * Checks if the undo and redo operations are currently blocked.
+     */
+    bool UndoRedoBlocked() const
+    {
+        return m_undoRedoBlocked;
+    }
+
+    /**
+     * Function UndoRedoBlock
+     * Enables/disable undo and redo operations.
+     */
+    void UndoRedoBlock( bool aBlock = true )
+    {
+        m_undoRedoBlocked = aBlock;
+    }
+
 protected:
     /// User defined rotation angle (in tenths of a degree).
     int m_rotationAngle;
 
+    /// Is undo/redo operation currently blocked?
+    bool m_undoRedoBlocked;
+
     /**
      * Function createArray
      * Create an array of the selected item (invokes the dialogue)
diff --git a/pcbnew/pcbframe.cpp b/pcbnew/pcbframe.cpp
index 8107d30c9b..33faef8e6c 100644
--- a/pcbnew/pcbframe.cpp
+++ b/pcbnew/pcbframe.cpp
@@ -679,6 +679,9 @@ void PCB_EDIT_FRAME::UseGalCanvas( bool aEnable )
 
         // Redirect all events to the legacy canvas
         GetGalCanvas()->SetEventDispatcher( NULL );
+
+        // No matter what, reenable undo/redo
+        UndoRedoBlock( false );
     }
 
     enableGALSpecificMenus();
diff --git a/pcbnew/router/length_tuner_tool.cpp b/pcbnew/router/length_tuner_tool.cpp
index 31877b997a..cc6bfd74bd 100644
--- a/pcbnew/router/length_tuner_tool.cpp
+++ b/pcbnew/router/length_tuner_tool.cpp
@@ -155,8 +155,6 @@ void LENGTH_TUNER_TOOL::updateStatusPopup( PNS_TUNE_STATUS_POPUP& aPopup )
 
 void LENGTH_TUNER_TOOL::performTuning()
 {
-    bool saveUndoBuffer = true;
-
     if( m_startItem )
     {
         m_frame->SetActiveLayer( ToLAYER_ID ( m_startItem->Layers().Start() ) );
@@ -187,16 +185,10 @@ void LENGTH_TUNER_TOOL::performTuning()
     m_router->Move( end, NULL );
     updateStatusPopup( statusPopup );
 
-
     while( OPT_TOOL_EVENT evt = Wait() )
     {
         if( evt->IsCancel() || evt->IsActivate() )
             break;
-        else if( evt->Action() == TA_UNDO_REDO )
-        {
-            saveUndoBuffer = false;
-            break;
-        }
         else if( evt->IsMotion() )
         {
             end = evt->Position();
@@ -239,21 +231,11 @@ void LENGTH_TUNER_TOOL::performTuning()
 
     m_router->StopRouting();
 
-    if( saveUndoBuffer )
-    {
-        // Save the recent changes in the undo buffer
-        m_frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
-        m_router->ClearUndoBuffer();
-        m_frame->OnModify();
-    }
-    else
-    {
-        // It was interrupted by TA_UNDO_REDO event, so we have to sync the world now
-        m_needsSync = true;
-    }
+    // Save the recent changes in the undo buffer
+    m_frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
+    m_router->ClearUndoBuffer();
+    m_frame->OnModify();
 
-    m_ctls->SetAutoPan( false );
-    m_ctls->ForceCursorPosition( false );
     highlightNet( false );
 }
 
@@ -290,6 +272,7 @@ int LENGTH_TUNER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
 
     m_ctls->SetSnapping( true );
     m_ctls->ShowCursor( true );
+    m_frame->UndoRedoBlock( true );
 
     std::auto_ptr<TUNER_TOOL_MENU> ctxMenu( new TUNER_TOOL_MENU( m_board ) );
     SetContextMenu( ctxMenu.get() );
@@ -306,23 +289,19 @@ int LENGTH_TUNER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
 
         if( evt->IsCancel() || evt->IsActivate() )
             break; // Finish
-        else if( evt->Action() == TA_UNDO_REDO )
-            m_needsSync = true;
         else if( evt->IsMotion() )
             updateStartItem( *evt );
         else if( evt->IsClick( BUT_LEFT ) || evt->IsAction( &ACT_StartTuning ) )
         {
             updateStartItem( *evt );
-            performTuning( );
+            performTuning();
         }
 
         handleCommonEvents( *evt );
     }
 
-    // Restore the default settings
-    m_ctls->SetAutoPan( false );
-    m_ctls->ShowCursor( false );
     m_frame->SetToolID( ID_NO_TOOL_SELECTED, wxCURSOR_DEFAULT, wxEmptyString );
+    m_frame->UndoRedoBlock( false );
 
     // Store routing settings till the next invocation
     m_savedSettings = m_router->Settings();
diff --git a/pcbnew/router/router_tool.cpp b/pcbnew/router/router_tool.cpp
index 2162fa5eaf..dc32cb95b8 100644
--- a/pcbnew/router/router_tool.cpp
+++ b/pcbnew/router/router_tool.cpp
@@ -471,22 +471,14 @@ bool ROUTER_TOOL::prepareInteractive()
 }
 
 
-bool ROUTER_TOOL::finishInteractive( bool aSaveUndoBuffer )
+bool ROUTER_TOOL::finishInteractive()
 {
     m_router->StopRouting();
 
-    if( aSaveUndoBuffer )
-    {
-        // Save the recent changes in the undo buffer
-        m_frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
-        m_router->ClearUndoBuffer();
-        m_frame->OnModify();
-    }
-    else
-    {
-        // It was interrupted by TA_UNDO_REDO event, so we have to sync the world now
-        m_needsSync = true;
-    }
+    // Save the recent changes in the undo buffer
+    m_frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
+    m_router->ClearUndoBuffer();
+    m_frame->OnModify();
 
     m_ctls->SetAutoPan( false );
     m_ctls->ForceCursorPosition( false );
@@ -498,8 +490,6 @@ bool ROUTER_TOOL::finishInteractive( bool aSaveUndoBuffer )
 
 void ROUTER_TOOL::performRouting()
 {
-    bool saveUndoBuffer = true;
-
     if( !prepareInteractive() )
         return;
 
@@ -507,11 +497,6 @@ void ROUTER_TOOL::performRouting()
     {
         if( evt->IsCancel() || evt->IsActivate() )
             break;
-        else if( evt->Action() == TA_UNDO_REDO )
-        {
-            saveUndoBuffer = false;
-            break;
-        }
         else if( evt->IsMotion() )
         {
             updateEndItem( *evt );
@@ -565,7 +550,7 @@ void ROUTER_TOOL::performRouting()
         handleCommonEvents( *evt );
     }
 
-    finishInteractive( saveUndoBuffer );
+    finishInteractive();
 }
 
 
@@ -628,6 +613,7 @@ int ROUTER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
 
     m_ctls->SetSnapping( true );
     m_ctls->ShowCursor( true );
+    frame->UndoRedoBlock( true );
 
     m_startSnapPoint = getViewControls()->GetCursorPosition();
 
@@ -646,8 +632,6 @@ int ROUTER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
 
         if( evt->IsCancel() || evt->IsActivate() )
             break; // Finish
-        else if( evt->Action() == TA_UNDO_REDO )
-            m_needsSync = true;
         else if( evt->IsMotion() )
             updateStartItem( *evt );
         else if( evt->IsClick( BUT_LEFT ) || evt->IsAction( &ACT_NewTrack ) )
@@ -669,6 +653,7 @@ int ROUTER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
     }
 
     frame->SetToolID( ID_NO_TOOL_SELECTED, wxCURSOR_DEFAULT, wxEmptyString );
+    frame->UndoRedoBlock( false );
 
     // Store routing settings till the next invocation
     m_savedSettings = m_router->Settings();
@@ -681,7 +666,6 @@ int ROUTER_TOOL::mainLoop( PNS_ROUTER_MODE aMode )
 void ROUTER_TOOL::performDragging()
 {
     PCB_EDIT_FRAME* frame = getEditFrame<PCB_EDIT_FRAME>();
-    bool saveUndoBuffer = true;
     VIEW_CONTROLS* ctls = getViewControls();
 
     bool dragStarted = m_router->StartDragging( m_startSnapPoint, m_startItem );
@@ -699,11 +683,6 @@ void ROUTER_TOOL::performDragging()
     {
         if( evt->IsCancel() || evt->IsActivate() )
             break;
-        else if( evt->Action() == TA_UNDO_REDO )
-        {
-            saveUndoBuffer = false;
-            break;
-        }
         else if( evt->IsMotion() )
         {
             updateEndItem( *evt );
@@ -721,18 +700,10 @@ void ROUTER_TOOL::performDragging()
     if( m_router->RoutingInProgress() )
         m_router->StopRouting();
 
-    if( saveUndoBuffer )
-    {
-        // Save the recent changes in the undo buffer
-        frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
-        m_router->ClearUndoBuffer();
-        frame->OnModify();
-    }
-    else
-    {
-        // It was interrupted by TA_UNDO_REDO event, so we have to sync the world now
-        m_needsSync = true;
-    }
+    // Save the recent changes in the undo buffer
+    frame->SaveCopyInUndoList( m_router->GetUndoBuffer(), UR_UNSPECIFIED );
+    m_router->ClearUndoBuffer();
+    frame->OnModify();
 
     m_startItem = NULL;
 
@@ -766,6 +737,7 @@ int ROUTER_TOOL::InlineDrag( const TOOL_EVENT& aEvent )
 
     ctls->ForceCursorPosition( false );
     ctls->SetAutoPan( true );
+    frame->UndoRedoBlock( true );
 
     bool saveUndoBuffer = true;
 
@@ -778,7 +750,6 @@ int ROUTER_TOOL::InlineDrag( const TOOL_EVENT& aEvent )
             saveUndoBuffer = false;
             break;
         }
-
         else if( evt->IsMotion() || evt->IsDrag( BUT_LEFT ) )
         {
             m_router->Move( p0, NULL );
@@ -802,6 +773,7 @@ int ROUTER_TOOL::InlineDrag( const TOOL_EVENT& aEvent )
 
     ctls->SetAutoPan( false );
     ctls->ShowCursor( false );
+    frame->UndoRedoBlock( false );
 
     return 0;
 }
diff --git a/pcbnew/router/router_tool.h b/pcbnew/router/router_tool.h
index 1dee8c1a31..08f2f84827 100644
--- a/pcbnew/router/router_tool.h
+++ b/pcbnew/router/router_tool.h
@@ -56,8 +56,8 @@ private:
     void switchLayerOnViaPlacement();
     bool onViaCommand( VIATYPE_T aType );
 
-    bool prepareInteractive( );
-    bool finishInteractive( bool aSaveUndoBuffer );
+    bool prepareInteractive();
+    bool finishInteractive();
 };
 
 #endif