rem: var elements = document.getElementsByClassName(className, $('tree')); 
add: var elements = Selector.findChildElements($('tree'), ['.'+className]); 
context: 	_registerDragDropHandlers: function(className) {		var elements = document.getElementsByClassName(className, $('tree'));		for (var i = 0; i < elements.length; i++) {			Event.observe(elements[i], 'mousedown', function(event) { DragDrop.dragElement(event); }, true);			Event.observe(elements[i], 'dragstart', function(event) { DragDrop.dragElement(event); }, false);			Event.observe(elements[i], 'mouseup',   function(event) { DragDrop.dropElement(event); }, false);		}	},
meta: 9100	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9100/80543fd902040a383bd9d5a53ca365e980f37b9c/tree.js/buggy/typo3/tree.js