Nginx hanging on restart

I'm having to run the nginx startup script in the background, or it does not return to the shell when run – it does this through either

service nginx start

.. or simply running ..

/etc/init.d/nginx

.. directly. I've having to run it in the background then disown it ..

Running on Ubuntu 14.04.2, Nginx v 1.4.6

nginx -V gives us:

nginx version: nginx/1.4.6 (Ubuntu)
built by gcc 4.8.2 (Ubuntu 4.8.2-19ubuntu1)
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_spdy_module --with-http_sub_module --with-http_xslt_module --with-mail --with-mail_ssl_module

.. and "bash -x nginx restart" returns ..

+ PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
+ DAEMON=/usr/sbin/nginx
+ NAME=nginx
+ DESC=nginx
+ '[' -f /etc/default/nginx ']'
+ . /etc/default/nginx
+ test -x /usr/sbin/nginx
+ set -e
+ . /lib/lsb/init-functions
+++ run-parts --lsbsysinit --list /lib/lsb/init-functions.d
++ for hook in '$(run-parts --lsbsysinit --list /lib/lsb/init-functions.d 2>/dev/null)'
++ '[' -r /lib/lsb/init-functions.d/20-left-info-blocks ']'
++ . /lib/lsb/init-functions.d/20-left-info-blocks
++ for hook in '$(run-parts --lsbsysinit --list /lib/lsb/init-functions.d 2>/dev/null)'
++ '[' -r /lib/lsb/init-functions.d/50-ubuntu-logging ']'
++ . /lib/lsb/init-functions.d/50-ubuntu-logging
+++ LOG_DAEMON_MSG=
++ FANCYTTY=
++ '[' -e /etc/lsb-base-logging.sh ']'
++ true
+ case "$1" in
+ echo -n 'Restarting nginx: '
Restarting nginx: + start-stop-daemon --stop --quiet --pidfile /var/run/nginx.pid --exec /usr/sbin/nginx
+ sleep 1
nginx.
+ test_nginx_config
+ /usr/sbin/nginx -t
+ return 0
+ start-stop-daemon --start --quiet --pidfile /var/run/nginx.pid --exec /usr/sbin/nginx --

.. and then nothing.

CONFIGS:

nginx.conf

# Generic startup file.
user www-data developers;

#ususally equal to number of CPU's you have. run command "grep processor /proc/cpuinfo | wc -l" to find it
worker_processes auto;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;

# Keeps the logs free of messages about not being able to bind().
daemon     off;

events {
    worker_connections  1024;
}

http {
#   rewrite_log on;

    include mime.types;
    default_type       application/octet-stream;
    access_log         /var/log/nginx/access.log;
    sendfile           on;
#   tcp_nopush         on;
    keepalive_timeout  3;
#   tcp_nodelay        on;
#   gzip               on;
        #php max upload limit cannot be larger than this
    client_max_body_size 13m;

fastcgi_buffers 16 16k;
fastcgi_buffer_size 32k;

    index              index.php index.html index.htm;

    # Upstream to abstract backend connection(s) for PHP.
    upstream php {
                #this should match value of "listen" directive in php-fpm pool
        server unix:/var/run/php5-fpm.sock;
    }

    include sites-enabled/*;
}

Any insights would be much appreciated.