rem: var bundle = document.getElementById("backgroundBundle"); 
add: var canvas = document.createElementNS(kHTML_NS, "canvas"); var width = this._monitor.boxObject.width; var height = this._monitor.boxObject.height; canvas.width = width; canvas.height = height; 
context:   _tileImage: function ()  {    var bundle = document.getElementById("backgroundBundle");    this._monitor.style.backgroundColor = "white";    var text = document.createElementNS(kXUL_NS, "label");    text.setAttribute("id", "noPreviewAvailable");    text.setAttribute("value", bundle.getString("DesktopBackgroundNoPreview"));    this._monitor.appendChild(text);  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10234/0f6c796a9092e485b60cb45ef78e7df257df2195/setDesktopBackground.js/buggy/browser/components/shell/content/setDesktopBackground.js