[Plugin: NextGEN Gallery] [Gallery not found]

Hi there,

I really hope this is a simple problem.

I created two galleries, added pictures into both and added both galleries into an album.

I am trying to get to display the pictures like they are shown at http://dpotter.net/technical/2008/05/nextgen-gallery-review-displaying-images-gallery/ using this code:

[nggallery id=3]

And I keep on getting this error message on my post:
[Gallery not found]

Does anyone know what I am doing wrong?

Thanks

http://wordpress.org/extend/plugins/nextgen-gallery/