うちはこんな感じで、普通に動きました。

#!/bin/sh
# $Id: xinitrc,v 1.2 2003/02/27 19:03:30 jharper Exp $
userresources=$HOME/.Xresources
usermodmap=$HOME/.xmodmap
sysresources=/etc/X11/xinit/.Xresources
sysmodmap=/etc/X11/xinit/.Xmodmap

# merge in defaults and keymaps

if [ -f $sysresources ]; then
xrdb -merge $sysresources
fi
if [ -f $sysmodmap ]; then
xmodmap $sysmodmap
fi
if [ -f $userresources ]; then
xrdb -merge $userresources
fi
if [ -f $usermodmap ]; then
xmodmap $usermodmap
fi
# start some nice programs
source /sw/bin/init.csh
xset fp+ /usr/X11R6/lib/X11/fonts/mplus &
# start the window manager
exec uxterm &
exec quartz-wm