rem: if (aEvent.target.selected) aEvent.target.setAttribute("last-selected", aEvent.target.selected.id); 
add: if (aEvent.target.selectedItem) aEvent.target.setAttribute("last-selected", aEvent.target.selectedItem.id); 
context: function onExtensionSelect(aEvent){  if (aEvent.target.selected)    aEvent.target.setAttribute("last-selected", aEvent.target.selected.id);  else    aEvent.target.removeAttribute("last-selected");}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/eeff8284185c873422464b5a58c40d3ccfca690c/extensions.js/clean/toolkit/mozapps/extensions/content/extensions.js