See if this helps:
Gnome Archive list
Note the first fix:
> > I try to install the gnomemeeting slackware package and i got this :
> > ORBit-ERROR **: Wrong permissions for /tmp/orbit-root
>
> You were probably running (installing) in a 'sudo' or 'su' session?
>
> Try manually changing the permissions on that file, and install again.
> Orbit checks owners (even when root!) and permissions.
>
> Or you could run from a native root-shell.