Is it possible to send me the faulty presentation? (alain@slide-effect.com) : if it is too big use services like https://www.yousendit.com (it is free).
Actually it resolved when I remade the presentation. I used the same effects, backgrounds, and transitions but on the new file it worked. Sorry I dont have the faulty one, I saved over it with the working presentation. Thanks for the great software, it has helped in a ton of my projects and presentations!