Menu error after unload in v5.1

below code in dhtmlxmenu.js: 636 has problem:

[code]dhx4.attachEvent(“_onGridClick”, this._bodyClick);

this.unload = function() {
	window.dhx4._eventable(this, "clear");


on unload, should detachEvent _onGridClick(the code window.dhx4._eventable(this, “clear”) can’t detachEvent _onGridClick),
otherwise, there will has memory leak, and _bodyClick will error, because that is null and that.conf
will error.

this._bodyClick = function(e) { e = e||event; if (e.button == 2 || (window.dhx4.isOpera && e.ctrlKey == true)) return; if (that.conf.context) { ... } }