Can't upload images to Slider

Hi,

I have installed the latest version of EBS. Now I want to add a slider to my homepage. The dialogue to input the slider data appears correctly, but it is not possible to upload an image to a slide. Why? Because the upload dialogue pops up behind (!) the slider dialogue. This behaviour is the same for Firefox and Chrome. See screenshot below:

https://www.dropbox.com/s/y2lpzwvtr4r0izk/wordpress.jpg

Any idea how to solve this?

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