add:  tree.appendChild(document.createElement('treechildren')); 
context: function save_initial_panels(){  var tree = document.getElementById('current-panels');  if (!tree.view) {    setTimeout(save_initial_panels, 0);  } else {    for (var i = 0; i < tree.view.rowCount; ++i) {      var item = tree.contentView.getItemAtIndex(i);      original_panels.push(item.id);    }  }}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/b4789216a1793b2c07d191d4d588a220b542354b/customize.js/clean/xpfe/components/sidebar/resources/customize.js