"Have you modified your web site / file permissons / rewrite rules of apache ?"
No, I haven´t. The only thing I´ve done, is CHMOD some of my php-files to 666, and 777.
I´ve reuploaded it, but it still doesn´t work.
I also tried to upload a very simple html-index file, but it didn´t work either.
"Delete all public_html"
I cannot delete this. My ftp-client says "access denied". I tried in another client, but without any luck.