Set showRoot on the folder tree for real (bug 371076).

browser/components/places/content/bookmarkProperties.xul

@@ -152,6 +152,7 @@
         height="150"
         persist="height"
         onselect="BookmarkPropertiesPanel.onFolderTreeSelect();"
+        showRoot="true"
         place="place:&folder=2&group=3&excludeItems=1&excludeQueries=1&excludeReadOnlyFolders=1"
         hidecolumnpicker="true">
     <treecols>