it's because Linux is case-sensitive.
I've restored ALL the site to its original form, it should work now.
I've uploaded the modified version in a subdirectory, for those who want to see the differences.
Original site:
http://www.soulfathermaps.de/
Modified site:
http://www.soulfathermaps.de/newsite...ing/index.html
Can people upload screenshots if they see a difference ?