If I start weston as root user, weston starts like expected.

When I start weston over the service /etc/init.d/weston start

I see following error message in westen.log, when the system come up.

failed to bind to /tmp/.X11-unix/X0: Permission denied

The folder has following rights:
drwxr-xr-x    2 root     root            40 Jun 10 12:04 .X11-unix

If I change the rights to 
drwxr-xrwx    2 root     root            40 Jun 10 12:04 .X11-unix

then it worked like expected.

What is the right configuration for .X11-unix?