When you enter in the Gallery index (http://www.planearium.de/sp-studio/forum/gallery/index.php) there are shown the latest images posted in 'Make a Whish', current contest, old contests, and personal albums.
I suggest that it should be better (if possible) to show a random picture in the contest's gallery, at least in the current contest.
Right now the latest image posted for the contest gives a slight advantage over the other participants because it's always showed.
For the closed contests could be the winner image and for the personal albums it's fine to show the last posted one.