Program: 98680
Project: 98680
Buggy source:
public Preferences(final Explorer controller,final EventBus bus,final Window parent){
  super(controller,bus,parent);
  setLabel(messages.getText(DIALOG_PREFERENCES_TITLE));
  mode=addDropDown(messages.getText(DIALOG_PREFERENCES_MODE),controller.getMode(),gridbag,c,Mode.values());
  render=addDropDown(messages.getText(DIALOG_PREFERENCES_RENDER),controller.getRender(),gridbag,c,Render.values());
  paletteFile=addDropDown(messages.getText(DIALOG_PREFERENCES_PALETTE_FILE),controller.getPaletteFile(),gridbag,c,Config.PALETTE_FILES);
  paletteSize=addProperty(messages.getText(DIALOG_PREFERENCES_PALETTE_SIZE),controller.getPaletteSize(),gridbag,c,new Utils.IntegerFormatter(0,256));
  seed=addProperty(messages.getText(DIALOG_PREFERENCES_PALETTE_SEED),controller.getSeed(),gridbag,c,new Utils.LongFormatter());
  threads=addProperty(messages.getText(DIALOG_PREFERENCES_THREADS),controller.getThreads(),gridbag,c,new Utils.IntegerFormatter(Config.MIN_THREADS,8));
  debug=addCheckBox(messages.getText(DIALOG_PREFERENCES_DEBUG),controller.isDebug(),gridbag,c);
  setAction(new AbstractAction(messages.getText(DIALOG_PREFERENCES_BUTTON_UPDATE)){
    @Override public void actionPerformed(    ActionEvent e){
      controller.setMode(mode.get().name());
      controller.setRender(render.get().name());
      controller.setPaletteFile(paletteFile.get());
      controller.setPaletteSize(paletteSize.get());
      controller.setSeed(seed.get());
      controller.setThreads(threads.get());
      controller.setDebug(debug.get());
      controller.loadColours();
      bus.post(controller.getIFS());
      setVisible(false);
    }
  }
);
  setCancel(messages.getText(DIALOG_PREFERENCES_BUTTON_CANCEL));
}

Fixed version (ground truth):
public Preferences(final Explorer controller,final EventBus bus,final Window parent){
  super(controller,bus,parent);
  setLabel(messages.getText(DIALOG_PREFERENCES_TITLE));
  mode=addDropDown(messages.getText(DIALOG_PREFERENCES_MODE),controller.getMode(),gridbag,c,Mode.values());
  render=addDropDown(messages.getText(DIALOG_PREFERENCES_RENDER),controller.getRender(),gridbag,c,Render.values());
  paletteFile=addDropDown(messages.getText(DIALOG_PREFERENCES_PALETTE_FILE),controller.getPaletteFile(),gridbag,c,Config.PALETTE_FILES);
  paletteSize=addProperty(messages.getText(DIALOG_PREFERENCES_PALETTE_SIZE),controller.getPaletteSize(),gridbag,c,new Utils.IntegerFormatter(0,256));
  seed=addProperty(messages.getText(DIALOG_PREFERENCES_PALETTE_SEED),controller.getSeed(),gridbag,c,new Utils.LongFormatter());
  threads=addProperty(messages.getText(DIALOG_PREFERENCES_THREADS),controller.getThreads(),gridbag,c,new Utils.IntegerFormatter(Config.MIN_THREADS,8));
  debug=addCheckBox(messages.getText(DIALOG_PREFERENCES_DEBUG),controller.isDebug(),gridbag,c);
  setAction(new AbstractAction(messages.getText(DIALOG_PREFERENCES_BUTTON_UPDATE)){
    @Override public void actionPerformed(    ActionEvent e){
      controller.setMode(mode.get().name());
      controller.setRender(render.get().name());
      controller.setPaletteFile(paletteFile.get());
      controller.setPaletteSize(paletteSize.get());
      controller.setSeed(seed.get());
      controller.setThreads(threads.get());
      controller.setDebug(debug.get());
      controller.loadColours();
      controller.getViewer().reset();
      setVisible(false);
    }
  }
);
  setCancel(messages.getText(DIALOG_PREFERENCES_BUTTON_CANCEL));
}