Index: trunk/src/org/openstreetmap/josm/actions/DeleteAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/DeleteAction.java	(revision 1086)
+++ trunk/src/org/openstreetmap/josm/actions/DeleteAction.java	(revision 1087)
@@ -3,4 +3,6 @@
 
 import static org.openstreetmap.josm.tools.I18n.tr;
+
+import java.util.Collection;
 
 import java.awt.event.ActionEvent;
@@ -9,11 +11,15 @@
 import org.openstreetmap.josm.Main;
 import org.openstreetmap.josm.tools.Shortcut;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.data.SelectionChangedListener;
 
-public final class DeleteAction extends JosmAction {
+public final class DeleteAction extends JosmAction implements SelectionChangedListener {
 
 	public DeleteAction() {
 		super(tr("Delete"), "dialogs/delete", tr("Delete selected objects."),
 		Shortcut.registerShortcut("system:delete", tr("Edit: {0}", tr("Delete")), KeyEvent.VK_DELETE, Shortcut.GROUP_DIRECT), true);
-		setEnabled(true);
+        DataSet.selListeners.add(this);
+		setEnabled(false);
 	}
 
@@ -22,3 +28,6 @@
 		        .doActionPerformed(e);
 	}
+    public void selectionChanged(Collection<? extends OsmPrimitive> newSelection) {
+        setEnabled(! newSelection.isEmpty());
+    }
 }
Index: trunk/src/org/openstreetmap/josm/actions/ZoomInAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/ZoomInAction.java	(revision 1086)
+++ trunk/src/org/openstreetmap/josm/actions/ZoomInAction.java	(revision 1087)
@@ -19,4 +19,5 @@
 
 	public void actionPerformed(ActionEvent e) {
+        if (Main.map == null) return;
 		double zoom = Main.map.mapView.getScale();
 		Main.map.mapView.zoomTo(Main.map.mapView.getCenter(), zoom * .9);
Index: trunk/src/org/openstreetmap/josm/actions/ZoomOutAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/ZoomOutAction.java	(revision 1086)
+++ trunk/src/org/openstreetmap/josm/actions/ZoomOutAction.java	(revision 1087)
@@ -19,4 +19,5 @@
 
 	public void actionPerformed(ActionEvent e) {
+        if (Main.map == null) return;
 		double zoom = Main.map.mapView.getScale();
 		Main.map.mapView.zoomTo(Main.map.mapView.getCenter(), zoom /.9);