Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 4118)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 4119)
@@ -568,4 +568,5 @@
         propertyData.setColumnIdentifiers(new String[]{tr("Key"),tr("Value")});
         propertyTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
+        propertyTable.getTableHeader().setReorderingAllowed(false);
         propertyTable.addMouseListener(new PopupMenuLauncher() {
             @Override
@@ -633,4 +634,5 @@
 
         TableColumnModel mod = membershipTable.getColumnModel();
+        membershipTable.getTableHeader().setReorderingAllowed(false);
         mod.getColumn(0).setCellRenderer(new DefaultTableCellRenderer() {
             @Override public Component getTableCellRendererComponent(JTable table, Object value,