its in LoadURL in the sprite plugin runtime.js
Acts.prototype.LoadURL = function (url_, resize_)
{
var img = new Image();
var this_ = this;
var curFrame_ = this.curFrame;
img.onload = function ()
{
curFrame_.texture_img = img;
curFrame_.offx = 0;
curFrame_.offy = 0;
curFrame_.width = img.width;
curFrame_.height = img.height;
curFrame_.spritesheeted = false;
--> curFrame.datauri = "";