diff --git a/common/gl_context_mgr.cpp b/common/gl_context_mgr.cpp
index 930e74b221..cf32fde430 100644
--- a/common/gl_context_mgr.cpp
+++ b/common/gl_context_mgr.cpp
@@ -102,7 +102,9 @@ void GL_CONTEXT_MANAGER::UnlockCtx( wxGLContext* aContext )
     }
     else
     {
-        wxLogDebug( "Trying to unlock GL context mutex from a wrong context" );
+        wxLogDebug(
+            "Trying to unlock GL context mutex from a wrong context: aContext %p m_glCtx %p",
+            aContext, m_glCtx );
     }
 }
 
diff --git a/pcbnew/dialogs/dialog_pad_properties.cpp b/pcbnew/dialogs/dialog_pad_properties.cpp
index 8bef1abfa2..867de3c352 100644
--- a/pcbnew/dialogs/dialog_pad_properties.cpp
+++ b/pcbnew/dialogs/dialog_pad_properties.cpp
@@ -153,6 +153,18 @@ void DIALOG_PAD_PROPERTIES::OnInitDialog( wxInitDialogEvent& event )
 }
 
 
+void DIALOG_PAD_PROPERTIES::OnCancel( wxCommandEvent& event )
+{
+    // Mandatory to avoid m_panelShowPadGal trying to draw something
+    // in a non valid context during closing process:
+    if( m_parent->IsGalCanvasActive() )
+        m_panelShowPadGal->StopDrawing();
+
+    // Now call default handler for wxID_CANCEL command event
+    event.Skip();
+}
+
+
 void DIALOG_PAD_PROPERTIES::enablePrimitivePage( bool aEnable )
 {
     // Enable or disable the widgets in page managing custom shape primitives
@@ -188,8 +200,8 @@ void DIALOG_PAD_PROPERTIES::prepareCanvas()
         m_panelShowPadGal->Show();
         m_panelShowPad->Hide();
         auto view = m_panelShowPadGal->GetView();
-        // gives a non null grid size (0.01mm) because GAL layer does not like a 0 size grid:
-        double gridsize = 0.01 * IU_PER_MM;
+        // gives a non null grid size (0.001mm) because GAL layer does not like a 0 size grid:
+        double gridsize = 0.001 * IU_PER_MM;
         view->GetGAL()->SetGridSize( VECTOR2D( gridsize, gridsize ) );
         view->Add( m_dummyPad );
         view->Add( m_axisOrigin );
diff --git a/pcbnew/dialogs/dialog_pad_properties.h b/pcbnew/dialogs/dialog_pad_properties.h
index 875b8b7af1..462859350d 100644
--- a/pcbnew/dialogs/dialog_pad_properties.h
+++ b/pcbnew/dialogs/dialog_pad_properties.h
@@ -6,10 +6,10 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2016 Jean-Pierre Charras, jp.charras at wanadoo.fr
+ * Copyright (C) 2017 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2013 Dick Hollenbeck, dick@softplc.com
  * Copyright (C) 2008-2013 Wayne Stambaugh <stambaughw@verizon.net>
- * Copyright (C) 1992-2016 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2017 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -113,6 +113,7 @@ private:
     // event handlers:
     void OnInitDialog( wxInitDialogEvent& event ) override;
     void OnResize( wxSizeEvent& event );
+	void OnCancel( wxCommandEvent& event ) override;
 
     void OnPadShapeSelection( wxCommandEvent& event ) override;
     void OnDrillShapeSelected( wxCommandEvent& event ) override;
diff --git a/pcbnew/dialogs/dialog_pad_properties_base.cpp b/pcbnew/dialogs/dialog_pad_properties_base.cpp
index 2425d7eae5..48183140c9 100644
--- a/pcbnew/dialogs/dialog_pad_properties_base.cpp
+++ b/pcbnew/dialogs/dialog_pad_properties_base.cpp
@@ -633,7 +633,7 @@ DIALOG_PAD_PROPERTIES_BASE::DIALOG_PAD_PROPERTIES_BASE( wxWindow* parent, wxWind
 	
 	bSizerDisplayPad->Add( m_panelShowPad, 4, wxRIGHT|wxTOP|wxEXPAND, 5 );
 	
-	m_panelShowPadGal = new PCB_DRAW_PANEL_GAL( this, -1, wxPoint( 0, 0 ), wxDefaultSize, m_galOptions, EDA_DRAW_PANEL_GAL::GAL_TYPE_CAIRO );
+	m_panelShowPadGal = new PCB_DRAW_PANEL_GAL( this, -1, wxPoint( 0, 0 ), wxDefaultSize, m_galOptions, EDA_DRAW_PANEL_GAL::GAL_TYPE_CAIRO);
 	bSizerDisplayPad->Add( m_panelShowPadGal, 4, wxEXPAND|wxRIGHT|wxTOP, 5 );
 	
 	
@@ -704,6 +704,7 @@ DIALOG_PAD_PROPERTIES_BASE::DIALOG_PAD_PROPERTIES_BASE( wxWindow* parent, wxWind
 	m_buttonGeometry->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::onGeometryTransform ), NULL, this );
 	m_buttonImport->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::onImportPrimitives ), NULL, this );
 	m_panelShowPad->Connect( wxEVT_PAINT, wxPaintEventHandler( DIALOG_PAD_PROPERTIES_BASE::OnPaintShowPanel ), NULL, this );
+	m_sdbSizerCancel->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::OnCancel ), NULL, this );
 }
 
 DIALOG_PAD_PROPERTIES_BASE::~DIALOG_PAD_PROPERTIES_BASE()
@@ -749,6 +750,7 @@ DIALOG_PAD_PROPERTIES_BASE::~DIALOG_PAD_PROPERTIES_BASE()
 	m_buttonGeometry->Disconnect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::onGeometryTransform ), NULL, this );
 	m_buttonImport->Disconnect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::onImportPrimitives ), NULL, this );
 	m_panelShowPad->Disconnect( wxEVT_PAINT, wxPaintEventHandler( DIALOG_PAD_PROPERTIES_BASE::OnPaintShowPanel ), NULL, this );
+	m_sdbSizerCancel->Disconnect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( DIALOG_PAD_PROPERTIES_BASE::OnCancel ), NULL, this );
 	
 }
 
diff --git a/pcbnew/dialogs/dialog_pad_properties_base.fbp b/pcbnew/dialogs/dialog_pad_properties_base.fbp
index ecb4639c44..2cdccf90c9 100644
--- a/pcbnew/dialogs/dialog_pad_properties_base.fbp
+++ b/pcbnew/dialogs/dialog_pad_properties_base.fbp
@@ -88,12 +88,12 @@
             <event name="OnSetFocus"></event>
             <event name="OnSize"></event>
             <event name="OnUpdateUI"></event>
-            <object class="wxBoxSizer" expanded="0">
+            <object class="wxBoxSizer" expanded="1">
                 <property name="minimum_size"></property>
                 <property name="name">m_MainSizer</property>
                 <property name="orient">wxVERTICAL</property>
                 <property name="permission">none</property>
-                <object class="sizeritem" expanded="0">
+                <object class="sizeritem" expanded="1">
                     <property name="border">5</property>
                     <property name="flag">wxEXPAND</property>
                     <property name="proportion">1</property>
@@ -10210,7 +10210,7 @@
                                         <property name="center_pane">0</property>
                                         <property name="class">PCB_DRAW_PANEL_GAL</property>
                                         <property name="close_button">1</property>
-                                        <property name="construction">m_panelShowPadGal = new PCB_DRAW_PANEL_GAL( this, -1, wxPoint( 0, 0 ), wxDefaultSize, m_galOptions, EDA_DRAW_PANEL_GAL::GAL_TYPE_CAIRO );</property>
+                                        <property name="construction">m_panelShowPadGal = new PCB_DRAW_PANEL_GAL( this, -1, wxPoint( 0, 0 ), wxDefaultSize, m_galOptions, EDA_DRAW_PANEL_GAL::GAL_TYPE_CAIRO);</property>
                                         <property name="context_help"></property>
                                         <property name="context_menu">1</property>
                                         <property name="declaration">PCB_DRAW_PANEL_GAL* m_panelShowPadGal;&#x0A;KIGFX::GAL_DISPLAY_OPTIONS m_galOptions;</property>
@@ -10379,7 +10379,7 @@
                         <property name="name">m_sdbSizer</property>
                         <property name="permission">protected</property>
                         <event name="OnApplyButtonClick"></event>
-                        <event name="OnCancelButtonClick"></event>
+                        <event name="OnCancelButtonClick">OnCancel</event>
                         <event name="OnContextHelpButtonClick"></event>
                         <event name="OnHelpButtonClick"></event>
                         <event name="OnNoButtonClick"></event>
diff --git a/pcbnew/dialogs/dialog_pad_properties_base.h b/pcbnew/dialogs/dialog_pad_properties_base.h
index f86e4fad4d..cfd8141e49 100644
--- a/pcbnew/dialogs/dialog_pad_properties_base.h
+++ b/pcbnew/dialogs/dialog_pad_properties_base.h
@@ -198,6 +198,7 @@ class DIALOG_PAD_PROPERTIES_BASE : public DIALOG_SHIM
 		virtual void onGeometryTransform( wxCommandEvent& event ) { event.Skip(); }
 		virtual void onImportPrimitives( wxCommandEvent& event ) { event.Skip(); }
 		virtual void OnPaintShowPanel( wxPaintEvent& event ) { event.Skip(); }
+		virtual void OnCancel( wxCommandEvent& event ) { event.Skip(); }
 		
 	
 	public: