animations no longer work when an easing.js plugin is included in the head, even if it isn't being used.

Using this code:

$(document).ready(function() {
  $('#container').fadeTo('slow',0.5);
});

Firebug returns this error:

"jQuery.easing[options.easing] is not a function" (jquery-1.1.3a.js, line 5159).

Test page at http://test.learningjquery.com/easing.html