rem: this._list.setAttribute("lastSelectedType", this._list.selectedItem.getAttribute("type")); 
add: if (this._list.selectedItem) this._list.setAttribute("lastSelectedType", this._list.selectedItem.getAttribute("type")); 
context:   onSelectionChanged: function() {    this._list.setAttribute("lastSelectedType",                            this._list.selectedItem.getAttribute("type"));  },
meta: 10520	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10520/06db904058b0d32cb66df87d1b95a17e32151691/applications.js/buggy/browser/components/preferences/applications.js