Hi Francis,
I got a way more familar now with this nginx config files. It works fine for me.

The only thing that I still not get figured out, is this FastCGI "Y" error.
It doesn't happen at the old webserver which is an apache/fastcgi environment, but I cannot play around with this, because it is just a webspace.

At the line 2287 there is this code
eval($s.";");

and
"FastCGI sent in stderr: "PHP message: PHP Notice: Use of undefined constant Y - assumed 'Y' in /xxx/front.func.inc.php(2287) : eval()'d code on line 1" while reading response header from upstream,..."

at line 1 in this file I can not see any Y?

I still hope the developer can give me some informations.

Daniel