Photo gallery MC


I´m trying to make working the photo gallery of the tutorial:

However, it doesn´t work because the following reason:
I´m trying to make a movie clip with this gallery. I create a new MC and paste in it the AS code in one layer, and a “photo” instance in another layer, like the tutorial does.
Then, I insert the MC in the scene but when i publish to swf it doesn´t work. The rectangle makes the effect, but in black (because the fill is black).
Could someone tell me how to solutionate this problem.