on FF 3.6 with no flash, onLoad event is not triggered

code to reproduce the error:
                    soundManager.createSound({
                        id: 'mysound',
                        url: '/sounds/mysound.ogg',
                        autoLoad: true,
                        autoPlay: true,
                        onload: function(){
                           alert('loaded');
                                }
                    });
adding s._a.load(); on line 2937, triggers the onload event.