Index: /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/DefaultMapController.java
===================================================================
--- /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/DefaultMapController.java	(revision 30402)
+++ /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/DefaultMapController.java	(revision 30403)
@@ -40,4 +40,5 @@
 
     public void mouseDragged(MouseEvent e) {
+        debugMouseEvent("DefaultMapController.mouseDragged", e);
         if (!movementEnabled || !isMoving)
             return;
@@ -55,4 +56,5 @@
 
     public void mouseClicked(MouseEvent e) {
+        debugMouseEvent("DefaultMapController.mouseClicked", e);
         if (doubleClickZoomEnabled && e.getClickCount() == 2 && e.getButton() == MouseEvent.BUTTON1) {
             map.zoomIn(e.getPoint());
@@ -61,4 +63,5 @@
 
     public void mousePressed(MouseEvent e) {
+        debugMouseEvent("DefaultMapController.mousePressed", e);
         if (e.getButton() == movementMouseButton || isPlatformOsx() && e.getModifiersEx() == MAC_MOUSE_BUTTON3_MASK) {
             lastDragPoint = null;
@@ -66,6 +69,7 @@
         }
     }
-
+    
     public void mouseReleased(MouseEvent e) {
+        debugMouseEvent("DefaultMapController.mouseReleased", e);
         if (e.getButton() == movementMouseButton || isPlatformOsx() && e.getButton() == MouseEvent.BUTTON1) {
             lastDragPoint = null;
@@ -74,4 +78,10 @@
     }
 
+    public void debugMouseEvent(String s, MouseEvent e) {
+        if (JMapViewer.debug) {
+            System.err.println("(#9897) " + s + ": Button "+ e.getButton() + " Modifiers: " +Integer.toBinaryString(e.getModifiersEx()));
+        }
+    }
+    
     public void mouseWheelMoved(MouseWheelEvent e) {
         if (wheelZoomEnabled) {
Index: /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java
===================================================================
--- /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java	(revision 30402)
+++ /applications/viewer/jmapviewer/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java	(revision 30403)
@@ -44,4 +44,6 @@
 
     private static final long serialVersionUID = 1L;
+    
+    public static boolean debug = false;
 
     /**