modal wrong position issue

I've made a new release fixing the following function:
```javascript

cacheSizes: function() {
          module.cache = {
            height        : $module.outerHeight() + settings.offset + window.parseInt($module.css('marginTop')),
            contextHeight : (settings.context == 'body')
              ? $(window).height()
              : $dimmable.height()
          };
          module.debug('Caching modal and container sizes', module.cache);
        }

```

Basically the modal cannot be scrolled when the page height is smaller than its height:

![modal](https://f.cloud.github.com/assets/879612/2147386/7d2e6b76-93d1-11e3-8254-fca82ac745dc.jpg)