Ops, sorry. It's www. Tht was a fault of mine and I corrected it. But it's the same result. Every .php-page shows 404 not found. And the dubug-log only complains about the favicon that cannot be found. But the file hello.php (a hello world script) definitely exists.

2012/03/22 10:08:40 [notice] 2900#0: *3 "^(GET|HEAD|POST)$" matches "GET", client: 127.0.0.1, server: www.example.com, request: "GET /hello.php HTTP/1.1", host: "www.example.com"
2012/03/22 10:08:40 [notice] 2900#0: *2 "^(GET|HEAD|POST)$" matches "GET", client: 127.0.0.1, server: www.example.com, request: "GET /favicon.ico HTTP/1.1", host: "www.example.com"
2012/03/22 10:08:40 [error] 2900#0: *2 open() "/www/example.com/public/favicon.ico" failed (2: No such file or directory), client: 127.0.0.1, server: www.example.com, request: "GET /favicon.ico HTTP/1.1", host: "www.example.com"
root@localhost:/var/log/nginx#

Thanks for your attention. But I think, I have to find another way of chrooting or abandon it.

Nginx is great. There is no alternative for me. For example the gzip-static module has no competition. ;-)