rem: prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranchInternal); 
add: prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranch2); 
context: function utilityOnUnload(aEvent) {  var observerService = Components.classes[kObserverServiceProgID]			  .getService(Components.interfaces.nsIObserverService);  observerService.removeObserver(offlineObserver, "network:offline-status-changed");  var prefService = Components.classes["@mozilla.org/preferences-service;1"];  prefService = prefService.getService(Components.interfaces.nsIPrefService);  var prefBranch = prefService.getBranch(null);  prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranchInternal);    prefBranch.removeObserver("network.proxy.type", proxyTypeObserver);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/331d73b7095bb826fff93981e5f30f40f21c0df7/utilityOverlay.js/clean/suite/common/utilityOverlay.js