Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java	(revision 9839)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/LayerListDialog.java	(revision 9840)
@@ -1656,8 +1656,15 @@
                     break;
                 case 1:
-                    if (Main.map.mapView.getNativeScaleLayer() == l) {
+                    NativeScaleLayer oldLayer = Main.map.mapView.getNativeScaleLayer();
+                    if (oldLayer == l) {
                         Main.map.mapView.setNativeScaleLayer(null);
                     } else if (l instanceof NativeScaleLayer) {
                         Main.map.mapView.setNativeScaleLayer((NativeScaleLayer) l);
+                        if (oldLayer != null) {
+                            int idx = getLayers().indexOf(oldLayer);
+                            if (idx >= 0) {
+                                fireTableCellUpdated(idx, col);
+                            }
+                        }
                     }
                     break;
Index: /trunk/src/org/openstreetmap/josm/gui/preferences/display/LafPreference.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/preferences/display/LafPreference.java	(revision 9839)
+++ /trunk/src/org/openstreetmap/josm/gui/preferences/display/LafPreference.java	(revision 9840)
@@ -13,9 +13,12 @@
 import javax.swing.DefaultListCellRenderer;
 import javax.swing.JCheckBox;
+import javax.swing.JFormattedTextField;
 import javax.swing.JLabel;
 import javax.swing.JList;
 import javax.swing.JScrollPane;
+import javax.swing.JSpinner;
 import javax.swing.ListCellRenderer;
 import javax.swing.LookAndFeel;
+import javax.swing.SpinnerNumberModel;
 import javax.swing.UIManager;
 import javax.swing.UIManager.LookAndFeelInfo;
@@ -24,4 +27,5 @@
 import org.openstreetmap.josm.actions.ExpertToggleAction;
 import org.openstreetmap.josm.gui.MapMover;
+import org.openstreetmap.josm.gui.NavigatableComponent;
 import org.openstreetmap.josm.gui.dialogs.ToggleDialog;
 import org.openstreetmap.josm.gui.preferences.PreferenceSetting;
@@ -64,4 +68,6 @@
     private final JCheckBox nativeFileChoosers = new JCheckBox(tr("Use native file choosers (nicer, but do not support file filters)"));
     private final JCheckBox zoomReverseWheel = new JCheckBox(tr("Reverse zoom with mouse wheel"));
+    private final JCheckBox zoomIntermediateSteps = new JCheckBox(tr("Intermediate steps between native resolutions"));
+    private JSpinner spinZoomRatio;
 
     @Override
@@ -148,5 +154,27 @@
         panel.add(zoomReverseWheel, GBC.eop().insets(20, 0, 0, 0));
 
-        panel.add(Box.createVerticalGlue(), GBC.eol().insets(0, 20, 0, 0));
+        zoomIntermediateSteps.setToolTipText(
+                tr("Divide intervals between native resolution levels to smaller steps if they are much larger than zoom ratio"));
+        zoomIntermediateSteps.setSelected(NavigatableComponent.PROP_ZOOM_INTERMEDIATE_STEPS.get());
+        ExpertToggleAction.addVisibilitySwitcher(zoomIntermediateSteps);
+        panel.add(zoomIntermediateSteps, GBC.eop().insets(20, 0, 0, 0));
+
+        panel.add(Box.createVerticalGlue(), GBC.eol().insets(0, 10, 0, 0));
+
+        double logZoomLevel = Math.log(2) / Math.log(NavigatableComponent.PROP_ZOOM_RATIO.get());
+        logZoomLevel = Math.max(1, logZoomLevel);
+        logZoomLevel = Math.min(5, logZoomLevel);
+        JLabel labelZoomRatio = new JLabel(tr("Zoom steps to get double scale"));
+        spinZoomRatio = new JSpinner(new SpinnerNumberModel(logZoomLevel, 1, 5, 1));
+        Component spinZoomRatioEditor = spinZoomRatio.getEditor();
+        JFormattedTextField jftf = ((JSpinner.DefaultEditor) spinZoomRatioEditor).getTextField();
+        jftf.setColumns(2);
+        String zoomRatioToolTipText = tr("Higher value means more steps needed, therefore zoom steps will be smaller");
+        spinZoomRatio.setToolTipText(zoomRatioToolTipText);
+        labelZoomRatio.setToolTipText(zoomRatioToolTipText);
+        labelZoomRatio.setLabelFor(spinZoomRatio);
+        panel.add(labelZoomRatio, GBC.std().insets(20, 0, 0, 0));
+        panel.add(GBC.glue(5, 0), GBC.std().fill(GBC.HORIZONTAL));
+        panel.add(spinZoomRatio, GBC.eol());
 
         panel.add(new JLabel(tr("Look and Feel")), GBC.std().insets(20, 0, 0, 0));
@@ -169,5 +197,7 @@
         Main.pref.put(DateUtils.PROP_ISO_DATES.getKey(), isoDates.isSelected());
         Main.pref.put(FileChooserManager.PROP_USE_NATIVE_FILE_DIALOG.getKey(), nativeFileChoosers.isSelected());
-        Main.pref.put(MapMover.PROP_ZOOM_REVERSE_WHEEL.getKey(), zoomReverseWheel.isSelected());
+        MapMover.PROP_ZOOM_REVERSE_WHEEL.put(zoomReverseWheel.isSelected());
+        NavigatableComponent.PROP_ZOOM_INTERMEDIATE_STEPS.put(zoomIntermediateSteps.isSelected());
+        NavigatableComponent.PROP_ZOOM_RATIO.put(Math.pow(2, 1/(double) spinZoomRatio.getModel().getValue()));
         mod |= Main.pref.put("laf", ((LookAndFeelInfo) lafCombo.getSelectedItem()).getClassName());
         return mod;