add:  return true; 
context:       onCancel:        function ()          {            for( var i = 0; i < hPrefWindow.cancelHandlers.length; i++ )              try {                hPrefWindow.cancelHandlers[i]();              } catch (e) {                dump("some silly cancel handler /*"+hPrefWindow.cancelHandlers[i]+"*/ failed: "+ e);              }          },
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/12b0dce117b973f932a32f53c4167652ad0051cb/nsPrefWindow.js/buggy/suite/common/pref/nsPrefWindow.js