JavaScript error

[Mythotical]

I know jack about JavaScript, I hope someone can help me out here.

I am using lightbox and I keep getting this error when I try to load the lightbox, it worked fine yesterday but now I'm getting this error.

element has no properties
remove(null)prototype.js (line 877)
activate()lightbox.js (line 164)
bindAsEventListener(click clientX=0, clientY=0)prototype.js (line 59)
[Break on this error] element.parentNode.removeChild(element);

Now this is from prototype and lightbox which is annoying the crap out of me.

prototype.js Line 877:

  remove: function(element) {
    element = $(element);
    element.parentNode.removeChild(element);
  },

Exact line 877:

element.parentNode.removeChild(element);

prototype.js Line 59:

Function.prototype.bindAsEventListener = function(object) {
  var __method = this;
  return function(event) {
    return __method.call(object, event || window.event);
  }
}

Exact line 59:

return __method.call(object, event || window.event);

lightbox.js Line 164:

	activate: function(){
		Element.remove($('lbContent'));

Exact line 164:

activate: function(){

Thanks in advance to anyone who can help

Cheers
Steve