Thank for your reply.
I checked my firebug but i can't really find what's wrong. I installed another slideshow module and it also doesn't appear.
Code:
TypeError: jQuery(...).show(...).nivoSlider is not a function
[Break On This Error]
afterLoad: function(){} });
rrdesign.nl (line 162)
TypeError: a.slideshow is not a function
[Break On This Error]
...en"),d=a.find(".wk-slideset").css("visibility","hidden"),e=d.find("ul.set > li")...
I also don't know why he is searching for a notifications.css as i don't know where that line is coming from.