On your settings page, Settings -> Reading, you can set the default home page. Here you can set it to ‘Your latest posts’ to display your blog.
If this doesn’t work, you will have to contact the creator of the theme because then it is a theme related issue.
Thanks for the help.
I have solved the problem by generating the fields with javascript and storing the values of all combo boxes in a hidden input with a correct wordpress name. I set this value with every onchange of a combo box.
The problem is that I would like to be able to create an unknown number of comboboxes.
I don’t know the number in advance.