Slideshow Navigation INACTIVE

I’m using WordPress 3.5.1., my theme supports all WordPress 3.0 features.
I installed the Portfolio Slightshow 1.5.0 but my slighshow doesn’t move. I followed the instructions as mentioned, insering the code [portfolio_slideshow id=294] in my post but the navigation isn’t active. I only see the first slight, the others are visible but inactive:

http://katharinahauswaldt.com/wordpress/texte/wortwechsel/?preview=true&preview_id=294&preview_nonce=575d3721f5

Does anybody has an idea?

http://ww.wp.xz.cn/extend/plugins/portfolio-slideshow/