Hello All, I have a little problem with Babylonjs

Hello to all and Merry chritmas:

I have a project and I want use Babylonjs.

I have include two lines

<script src="librerias/babylon2/babylon.2.2.max.js"></script>
<script src="librerias/babylon2/Materiales/babylon.simpleMaterial.js"></script>

If I comment the second line (load simpleMaterial.js) all are ok, but no simple material are defined, obviusly.

But if I try to load any file material, (fire, water, simple, etc) I recieve one error, and c'ant continue

0x800a138f - Error in execution time JavaScript: C'ant obtain the property  "prototype" is null o not defined.

in line 4, position 1 of babylon.2.2.max.js file.

Sorry by my english, i am spanish developer.

What I do bad ?

Thanks for all.