[jQuery] Problem with Interface > droppable > onhover

[NccWarp9]

I have a problem with whis:
                        $('#drag').Draggable();
                        $('#holder .dropzone').Droppable({
                                        accept :                'dropaccept',
                                        activeclass:    'dropactive',
                                        hoverclass:     'dropzonehover',
                                        tolerance:      'pointer',
                                        ondrop: function (drag) {
                                                              alert(this); //the
droppable
                                                              alert(drag); //the
draggable
                                                                },
                                        onHover: function(drag) { alert(this); 
//the droppable }
                        });

when I remove onhover line it works but if I add it it sops working,
and ideas?
it is driving me nuts...