Picture didn't 'open'

Hello,

I juste updated my next-gen gallery to 2.0.7 and i have an issue :

Now, when i click on a thumbnail, the picture open with the browser. It didn’t open with the effect (when you see the picture and you can navigate with the “<<” and “>>”).

Can you help me ?
Thanks.

(Sorry for my language).

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