Make roar works with mootools 1.4.x

Roar.css

.roar-body
{
	position:				absolute;
	font:					12px/14px "Lucida Grande", Arial, Helvetica, Verdana, sans-serif;
	color:					#fff;
	text-align:				left;
	z-index:				999;
}

.roar
{
	position:				absolute;
	width:					300px;
	cursor:					pointer;
}
.roar-bg
{
	position:				absolute;
	z-index:				1000;
	width:					100%;
	height:					100%;
	left:					0;
	top:					0;
	background-color:		#000;
	border-radius:		10px;
}
.roar-body-ugly .roar
{
	background-color:		#333;
}
.roar-body-ugly .roar-bg
{
	display:				none;
}
.roar h3
{
	position:				relative;
	padding:				15px 10px 0;
	margin:					0;
	border:					0;
	font-size:				13px;
	color:					#fff;
	z-index:				1002;
}
.roar p
{
	position:				relative;
	padding:				10px 10px 15px;
	margin:					0;
	font-size:				12px;
	color:					#fff;
	z-index:				1002;
}

Roar.js

/**
 * Roar - Notifications
 *
 * Inspired by Growl
 *
 * @version		1.0.1
 *
 * @license		MIT-style license
 * @author		Harald Kirschner <mail [at] digitarald.de>
 * @copyright	Author
 */

var Roar = new Class({

	Implements: [Options, Events, Chain],

	options: {
		duration: 3000,
		position: 'upperLeft',
		container: null,
		bodyFx: null,
		itemFx: null,
		margin: {x: 10, y: 10},
		offset: 10,
		className: 'roar',
		onShow: Function.from(),
		onHide: Function.from(),
		onRender: Function.from()
	},

	initialize: function(options) {
		this.setOptions(options);
		this.items = [];
		this.container = $(this.options.container) || document;
	},

	alert: function(title, message, options) {
		var params = Array.link(arguments, {title: Type.isString, message: Type.isString, options: Type.isObject});
		var items = [new Element('h3', {'html': Array.pick([params.title, ''])})];
		if (params.message) items.push(new Element('p', {'html': params.message}));
		return this.inject(items, params.options);
	},

	inject: function(elements, options) {
		if (!this.body) this.render();
		options = options || {};

		var offset = [-this.options.offset, 0];
		var last = this.items.getLast();
		if (last) {
			offset[0] = last.retrieve('roar:offset');
			offset[1] = offset[0] + last.offsetHeight + this.options.offset;
		}
		var to = {'opacity': 1};
		to[this.align.y] = offset;

		var item = new Element('div', {
			'class': this.options.className,
			'opacity': 0
		}).adopt(
			new Element('div', {
				'class': 'roar-bg',
				'style': {'opacity': 0.7}
			}),
			elements
		);

		item.setStyle(this.align.x, 0).store('roar:offset', offset[1]).set('morph', Object.merge({
			link: 'cancel',
			onStart: Chain.prototype.clearChain,
			transition: Fx.Transitions.Back.easeOut
		}, this.options.itemFx));

		var remove = this.remove.bind(this, item);
		this.items.push(item.addEvent('click', remove));

		if (this.options.duration) {
			var over = false;
			var trigger = (function() {
				trigger = null;
				if (!over) remove();
			}).delay(this.options.duration);
			item.addEvents({
				mouseover: function() {
					over = true;
				},
				mouseout: function() {
					over = false;
					if (!trigger) remove();
				}
			});
		}
		item.inject(this.body).morph(to);
		return this.fireEvent('onShow', [item, this.items.length]);
	},

	remove: function(item) {
		var index = this.items.indexOf(item);
		if (index == -1) return this;
		this.items.splice(index, 1);
		item.removeEvents();
		var to = {opacity: 0};
		to[this.align.y] = item.getStyle(this.align.y).toInt() - item.offsetHeight - this.options.offset;
		item.morph(to).get('morph').chain(item.destroy.bind(item));
		return this.fireEvent('onHide', [item, this.items.length]).callChain(item);
	},

	empty: function() {
		while (this.items.length) this.remove(this.items[0]);
		return this;
	},

	render: function() {
		this.position = this.options.position;
		if (typeOf(this.position) == 'string') {
			var position = {x: 'center', y: 'center'};
			this.align = {x: 'left', y: 'top'};
			if ((/left|west/i).test(this.position)) position.x = 'left';
			else if ((/right|east/i).test(this.position)) this.align.x = position.x = 'right';
			if ((/upper|top|north/i).test(this.position)) position.y = 'top';
			else if ((/bottom|lower|south/i).test(this.position)) this.align.y = position.y = 'bottom';
			this.position = position;
		}
		this.body = new Element('div', {'class': 'roar-body'}).inject(document.body);
		if (Browser.ie) this.body.addClass('roar-body-ugly');
		this.moveTo = this.body.setStyles.bind(this.body);
		this.reposition();
		if (this.options.bodyFx) {
			var morph = new Fx.Morph(this.body, Object.merge({
				unit: 'px',
				chain: 'cancel',
				transition: Fx.Transitions.Circ.easeOut
			}, this.options.bodyFx));
			this.moveTo = morph.start.bind(morph);
		}
		var repos = this.reposition.bind(this);
		window.addEvents({
			scroll: repos,
			resize: repos
		});
		this.fireEvent('onRender', this.body);
	},

	reposition: function() {
		var max = document.getCoordinates(), scroll = document.getScroll(), margin = this.options.margin;
		max.left += scroll.x;
		max.right += scroll.x;
		max.top += scroll.y;
		max.bottom += scroll.y;
		var rel = (typeOf(this.container) == 'element') ? this.container.getCoordinates() : max;
		this.moveTo({
			left: (this.position.x == 'right')
				? (Math.min(rel.right, max.right) - margin.x)
				: (Math.max(rel.left, max.left) + margin.x),
			top: (this.position.y == 'bottom')
				? (Math.min(rel.bottom, max.bottom) - margin.y)
				: (Math.max(rel.top, max.top) + margin.y)
		});
	}

});

Hi!

I made a fork of this gist and made a simple modification, to work on current browsers. The problem was obvious based on your modifications.

Have a look at my fork and update your gist if you wish.