sockets not working

thin -s20 -eproduction --socket /tmp/thin.sock -V start

thin.0.log:

>> Writing PID to tmp/pids/thin.0.pid
>> Thin web server (v0.6.3 codename Ninja Cookie)
>> Listening on /tmp/thin.0.sock, CTRL+C to stop
Unexpected error while processing request: not an AF_UNIX sockaddr
Unexpected error while processing request: not an AF_UNIX sockaddr
Unexpected error while processing request: not an AF_UNIX sockaddr

using nginx

nginx_errors.log
2008/02/12 13:30:25 [error] 7683#0: 293 upstream prematurely closed connection while reading response header from upstream, client: *..., server: example.com, request: "GET / HTTP/1.1", upstream: "http://unix:/tmp/thin.0.sock:/", host: "example.com"

Unix config: http://pastie.caboo.se/151341