I face a little issue with dhtmlxTree: nodes are not loading if I try scrolling the tree at a considerable speed with smart rendering on. My code (without data) is the next:
myTree = new dhtmlXTreeObject("treeboxbox_tree", "100%", "100%", 0);
myTree.setImagePath("…/images/");
myTree.setXMLAutoLoading("php/json.php");
//myTree.setXMLAutoLoading("…/php/json.php");
myTree.setDataMode("json");
myTree.enableSmartRendering(true);
//load first level of tree
myTree.loadJSON("php/json.php?id=0");
Smart rendering and dynamic loading are not compatible in dhtmlxTree. You can try dhtmlxTreeGrid to use these 2 modes together