add: dump("Exception caught in 'panelOnCancel': " + ex + "\n"); 
context:     panelOnCancel: function () {        for (var i=0; i < parent.backupPrefList.length; i++) {            if (parent.backupPrefList[i].color == "##NEW") {                try {                   categoryPrefBranch.clearUserPref(parent.backupPrefList[i].name);                } catch (ex) {                }            } else {                categoryPrefBranch.setCharPref(parent.backupPrefList[i].name,                                               parent.backupPrefList[i].color);            }        }    }
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/d637ae6ad43674a7a647b13f316377eb2b3f34c2/categories.js/clean/calendar/base/content/preferences/categories.js