Index: src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java
===================================================================
--- src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java	(revision 4709)
+++ src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java	(working copy)
@@ -442,7 +442,7 @@
             putValue(SMALL_ICON, ImageProvider.get("dialogs", "showhide"));
             putValue(SHORT_DESCRIPTION, tr("Toggle visible state of the selected layer."));
             putValue("help", HelpUtil.ht("/Dialog/LayerList#ShowHideLayer"));
-            putValue(ACCELERATOR_KEY, Shortcut.registerShortcut("core_multikey:showHideLayer", "", 'S', Shortcut.GROUP_DIRECT, KeyEvent.ALT_DOWN_MASK + KeyEvent.CTRL_DOWN_MASK).getKeyStroke());
+            putValue(ACCELERATOR_KEY, Shortcut.registerShortcut("core_multikey:showHideLayer", "", 'S', Shortcut.GROUP_DIRECT, KeyEvent.SHIFT_DOWN_MASK).getKeyStroke());
             if (init) {
                 updateEnabledState();
             }
@@ -629,7 +629,7 @@
         public ActivateLayerAction() {
             putValue(SMALL_ICON, ImageProvider.get("dialogs", "activate"));
             putValue(SHORT_DESCRIPTION, tr("Activate the selected layer"));
-            putValue(ACCELERATOR_KEY, Shortcut.registerShortcut("core_multikey:activateLayer", "", 'A', Shortcut.GROUP_DIRECT, KeyEvent.SHIFT_DOWN_MASK + KeyEvent.ALT_DOWN_MASK).getKeyStroke());
+            putValue(ACCELERATOR_KEY, Shortcut.registerShortcut("core_multikey:activateLayer", "", 'A', Shortcut.GROUP_DIRECT, KeyEvent.SHIFT_DOWN_MASK).getKeyStroke());
             putValue("help", HelpUtil.ht("/Dialog/LayerList#ActivateLayer"));
         }
 
Index: src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java
===================================================================
--- src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java	(revision 4709)
+++ src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java	(working copy)
@@ -89,6 +89,7 @@
 
         SwingUtilities.invokeLater(new Runnable(){
             public void run() {
+                if (Main.map==null || Main.map.mapView==null) return;
                 Main.map.mapView.addMouseListener(new MouseAdapter() {
                     @Override public void mousePressed(MouseEvent e) {
                         if (e.getButton() != MouseEvent.BUTTON1)
Index: src/org/openstreetmap/josm/actions/CreateMultipolygonAction.java
===================================================================
--- src/org/openstreetmap/josm/actions/CreateMultipolygonAction.java	(revision 4709)
+++ src/org/openstreetmap/josm/actions/CreateMultipolygonAction.java	(working copy)
@@ -48,7 +48,7 @@
     public CreateMultipolygonAction() {
         super(tr("Create multipolygon"), "multipoly_create", tr("Create multipolygon."),
                 Shortcut.registerShortcut("tools:multipoly", tr("Tool: {0}", tr("Create multipolygon")),
-                        KeyEvent.VK_A, Shortcut.GROUP_EDIT, Shortcut.SHIFT_DEFAULT), true);
+                        KeyEvent.VK_A, Shortcut.GROUP_DIRECT, KeyEvent.ALT_DOWN_MASK | KeyEvent.CTRL_DOWN_MASK ), true);
     }
     /**
      * The action button has been clicked