Homepage not showing

HI I'm new to WP and have set up a page using Catch Kathmandu. At the beginning the theme worked great. Unfortunately after installing SimpleViewer the Homepage won't show. Of course this could easily be caused by something else. The effect is that as the homepage a category is shown instead of the homepage with the slider images. I have tried for several days to fix this problems but with poor results. My web site is www.dambar.com.pl As you can see the homepage of this website is the category "Relacja" but I would like to get the slider images (only on the homepage) back again.