diff --git a/GUI/Widgets/Fl_Canvas.C b/GUI/Widgets/Fl_Canvas.C
index 1668499..e4b1e2e 100644
--- a/GUI/Widgets/Fl_Canvas.C
+++ b/GUI/Widgets/Fl_Canvas.C
@@ -603,7 +603,7 @@ int Fl_Canvas::handle(int event)
 				m_HaveSelection = false;
 			}   
 
-			if ((Fl::event_state() & FL_CTRL) != 0)
+			if (((Fl::event_state() & FL_CTRL) != 0) || ((Fl::event_state() & FL_SHIFT) != 0))
 			{
 				m_Selecting = true;
 				m_StartSelectX=Fl::event_x();
@@ -700,7 +700,7 @@ int Fl_Canvas::handle(int event)
 		}	
 	}
 
-	if ((Fl::event_button()==3) && (event==FL_PUSH)  && ((Fl::event_state() & FL_CTRL) != 0))
+	if ((Fl::event_button()==3) && (event==FL_PUSH))
 	{
 		PopupEditMenu(this);
 	}			
diff --git a/GUI/Widgets/Fl_Canvas.h b/GUI/Widgets/Fl_Canvas.h
index 750eae4..522880a 100644
--- a/GUI/Widgets/Fl_Canvas.h
+++ b/GUI/Widgets/Fl_Canvas.h
@@ -204,27 +204,35 @@ private:
 			PopupEditMenu(widget->parent());
 		}
 		
-		if ((widget) && (button==1) && ((shift_state & FL_CTRL) != 0))
-		{	
+		if ((widget) && (button==1))
+		{
 			int ID = ((Fl_DeviceGUI*)(widget->parent()))->GetID();
 			std::vector<int>::iterator device_iter = std::find(m_Selection.m_DeviceIds.begin(), m_Selection.m_DeviceIds.end(), ID);
 
-			if (m_HaveSelection)
-			{
-				if (device_iter != m_Selection.m_DeviceIds.end())
-					m_Selection.m_DeviceIds.erase(device_iter);				
+			if (((shift_state & FL_SHIFT) != 0) || ((shift_state & FL_CTRL) != 0))
+			{		
+				if (m_HaveSelection)
+				{
+					if (device_iter != m_Selection.m_DeviceIds.end())
+						m_Selection.m_DeviceIds.erase(device_iter);				
+					else
+						m_Selection.m_DeviceIds.push_back(ID);				
+				} 
 				else
-					m_Selection.m_DeviceIds.push_back(ID);				
-			} 
+				{
+					m_Selection.Clear();
+					m_HaveSelection = true;
+					m_Selection.m_DeviceIds.push_back(ID);
+				}
+			}
 			else
 			{
 				m_Selection.Clear();
 				m_HaveSelection = true;
 				m_Selection.m_DeviceIds.push_back(ID);
 			}
-			
-			redraw();		
-		}
+			redraw();
+		}	
 	}
 
        	inline void cb_DeleteDeviceGroup_i();