Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/ToggleDialog.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/ToggleDialog.java	(revision 1998)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/ToggleDialog.java	(revision 1999)
@@ -165,5 +165,7 @@
             public void actionPerformed(ActionEvent e) {
                 final JDialog f = new JDialog(JOptionPane.getFrameForComponent(Main.parent),false /* not modal*/);
-                parent.remove(ToggleDialog.this);
+                if (parent != null) {
+                    parent.remove(ToggleDialog.this);
+                }
                 f.getContentPane().add(ToggleDialog.this);
                 f.addWindowListener((winadapter = new WindowAdapter(){
@@ -201,7 +203,9 @@
                 titleBar.setVisible(false);
 
-                // doLayout() - workaround
-                parent.setVisible(false);
-                parent.setVisible(true);
+                if (parent != null) {
+                    // doLayout() - workaround
+                    parent.setVisible(false);
+                    parent.setVisible(true);
+                }
             }
         };