alt="" attribute is empty in Slider

Hello again,

when I use the Savia-Slider, the alt=”" attribute is empty.

Example:
[slider animation="fade" speed="6000"]
[slide link="" title=""]http://website.de/image1[/slide]
[slide link="" title=""]http://website.de/image2[/slide]
[/slider]

when I look into the source code I see this:
<img alt=”" src=”http://website.de/image1″ />

How can I solve this problem?! Please help me Thanks a lot!