Shop and Forum is folders below htdocs, so there should not be needed to set them up as aliases.
If you go to http://188.8.131.52/
you will be redirected to http://184.108.40.206/xampp/splas.php
as you said. But can open all the pages? F.ex. "Phpmyadmin"? If you do so you will see the splashmenu to the left, then phpmyadmin-meny in the middle, but where th elast page to the left should be you get page not found. That's what I get when I use another computer.
The path is correct, but in someway it can't get the info from MySql, and as you said, MySql is working...
That's why I can't find the problem. It might be something with the values in the "httpd.conf"-file, but I don't know where