Change your folder to kuvat, not Kuvat Case sensitive makes the difference
Your website is currently looking for this image: http://artotek.capoverde.fi/kuvat/3.gif Not found
Going to : http://artotek.capoverde.fi/Kuvat/3.gif Image is here Voila!
Rename your Kuvat folder to kuvat and your website will know where to find your images