add:  if (event.button != 0) return;  
context: function onFilterDoubleClick(event){    var t = event.originalTarget;    if (t.parentNode.parentNode.localName == "treeitem")        onEditFilter();}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/d33bd7b90e2d3cb35d10884d51a405c20dbd0be1/FilterListDialog.js/buggy/mailnews/base/search/resources/content/FilterListDialog.js