Program: 178170
Project: 178170
Buggy source:
public void initGui(){
  List<GuiButton> controlList=new LinkedList<GuiButton>();
  Point p=new Point();
  int i=0;
  moveToButtonCoords(1,p);
  controlList.add(new GuiButton(ID_EDITRULES,p.getX() + 55,height / 6 + 96,"String_Node_Str"));
  controlList.add(new GuiButton(ID_EDITTREE,p.getX() + 55,height / 6 + 120,"String_Node_Str"));
  controlList.add(new GuiButton(ID_HELP,p.getX() + 55,height / 6 + 144,"String_Node_Str"));
  controlList.add(new GuiButton(ID_DONE,p.getX() + 55,height / 6 + 168,"String_Node_Str"));
  String middleClick=config.getProperty(InvTweaksConfig.PROP_ENABLE_MIDDLE_CLICK);
  moveToButtonCoords(i++,p);
  GuiTooltipButton middleClickBtn=new GuiTooltipButton(ID_MIDDLE_CLICK,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_MIDDLE_CLICK,MIDDLE_CLICK),"String_Node_Str");
  controlList.add(middleClickBtn);
  if (middleClick.equals(InvTweaksConfig.VALUE_CI_COMPATIBILITY)) {
    middleClickBtn.enabled=false;
    middleClickBtn.setTooltip(middleClickBtn.getTooltip() + "String_Node_Str");
  }
  moveToButtonCoords(i++,p);
  controlList.add(new GuiTooltipButton(ID_SHORTCUTS_HELP,p.getX() + 130,p.getY(),20,20,"String_Node_Str","String_Node_Str"));
  controlList.add(new GuiTooltipButton(ID_SHORTCUTS,p.getX(),p.getY(),130,20,computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_SHORTCUTS,SHORTCUTS),"String_Node_Str"));
  moveToButtonCoords(i++,p);
  GuiTooltipButton sortOnPickupBtn=new GuiTooltipButton(ID_SORT_ON_PICKUP,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_SORTING_ON_PICKUP,SORT_ON_PICKUP),"String_Node_Str");
  controlList.add(sortOnPickupBtn);
  if (mc.isMultiplayerWorld()) {
    sortOnPickupBtn.enabled=false;
    sortOnPickupBtn.displayString=SORT_ON_PICKUP + SP_ONLY;
    sortOnPickupBtn.setTooltip(sortOnPickupBtn.getTooltip() + "String_Node_Str");
  }
  moveToButtonCoords(i++,p);
  controlList.add(new GuiTooltipButton(ID_CHESTS_BUTTONS,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_SHOW_CHEST_BUTTONS,CHEST_BUTTONS),"String_Node_Str"));
  if (!Desktop.isDesktopSupported()) {
    for (    Object o : controlList) {
      GuiButton button=(GuiButton)o;
      if (button.id == ID_EDITRULES || button.id < ID_EDITTREE) {
        button.enabled=false;
      }
    }
  }
  this.controlList=controlList;
}

Fixed version (ground truth):
public void initGui(){
  List<GuiButton> controlList=new LinkedList<GuiButton>();
  Point p=new Point();
  int i=0;
  moveToButtonCoords(1,p);
  controlList.add(new GuiButton(ID_EDITRULES,p.getX() + 55,height / 6 + 96,"String_Node_Str"));
  controlList.add(new GuiButton(ID_EDITTREE,p.getX() + 55,height / 6 + 120,"String_Node_Str"));
  controlList.add(new GuiButton(ID_HELP,p.getX() + 55,height / 6 + 144,"String_Node_Str"));
  controlList.add(new GuiButton(ID_DONE,p.getX() + 55,height / 6 + 168,"String_Node_Str"));
  String middleClick=config.getProperty(InvTweaksConfig.PROP_ENABLE_MIDDLE_CLICK);
  moveToButtonCoords(i++,p);
  GuiTooltipButton middleClickBtn=new GuiTooltipButton(ID_MIDDLE_CLICK,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_MIDDLE_CLICK,MIDDLE_CLICK),"String_Node_Str");
  controlList.add(middleClickBtn);
  if (middleClick.equals(InvTweaksConfig.VALUE_CI_COMPATIBILITY)) {
    middleClickBtn.enabled=false;
    middleClickBtn.setTooltip(middleClickBtn.getTooltip() + "String_Node_Str");
  }
  moveToButtonCoords(i++,p);
  controlList.add(new GuiTooltipButton(ID_SHORTCUTS_HELP,p.getX() + 130,p.getY(),20,20,"String_Node_Str","String_Node_Str"));
  String shortcuts=config.getProperty(InvTweaksConfig.PROP_ENABLE_SHORTCUTS);
  GuiTooltipButton shortcutsBtn=new GuiTooltipButton(ID_SHORTCUTS,p.getX(),p.getY(),130,20,computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_SHORTCUTS,SHORTCUTS),"String_Node_Str");
  controlList.add(shortcutsBtn);
  if (shortcuts.equals(InvTweaksConfig.VALUE_CI_COMPATIBILITY)) {
    shortcutsBtn.enabled=false;
    shortcutsBtn.setTooltip(shortcutsBtn.getTooltip() + "String_Node_Str");
  }
  moveToButtonCoords(i++,p);
  GuiTooltipButton sortOnPickupBtn=new GuiTooltipButton(ID_SORT_ON_PICKUP,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_ENABLE_SORTING_ON_PICKUP,SORT_ON_PICKUP),"String_Node_Str");
  controlList.add(sortOnPickupBtn);
  if (mc.isMultiplayerWorld()) {
    sortOnPickupBtn.enabled=false;
    sortOnPickupBtn.displayString=SORT_ON_PICKUP + SP_ONLY;
    sortOnPickupBtn.setTooltip(sortOnPickupBtn.getTooltip() + "String_Node_Str");
  }
  moveToButtonCoords(i++,p);
  controlList.add(new GuiTooltipButton(ID_CHESTS_BUTTONS,p.getX(),p.getY(),computeBooleanButtonLabel(InvTweaksConfig.PROP_SHOW_CHEST_BUTTONS,CHEST_BUTTONS),"String_Node_Str"));
  if (!Desktop.isDesktopSupported()) {
    for (    Object o : controlList) {
      GuiButton button=(GuiButton)o;
      if (button.id == ID_EDITRULES || button.id < ID_EDITTREE) {
        button.enabled=false;
      }
    }
  }
  this.controlList=controlList;
}