I just like space :-) The if is a wee misformatted.

	public function SubsiteMainMenu(){
		if(Subsite::currentSubsiteID() == 0){
			return $this->owner->MainMenu();
		}

		// loop main menu items, add all items that have subsite support
		$mainMenu = $this->owner->MainMenu();
		$subsitesMenu = new ArrayList();
		foreach($mainMenu as $menuItem) {

			$controllerName = $menuItem->MenuItem->controller;

			if(class_exists($controllerName)) {
				$controller = singleton($controllerName);
				if($controller->hasMethod('subsiteMenu') && $controller->subsiteMenu()) {
					$subsitesMenu->push($menuItem);
				}
			}

			if($menuItem->Code == 'Help'){
				$subsitesMenu->push($menuItem);
			}

		}

		return $subsitesMenu;
	}