xhost hangs

All,
I am trying to connect to another system’s display, but first I must run ‘xhost +’ or ‘xhost ‘. After logging into the Xserver I:
ksh
export XAUTHORITY=`/usr/ucb/ps -auxwwww |grep “[X]sun” |sed ‘s/.* //’`
export DISPLAY=:0
xhost +
and it hangs on ‘xhost +’. The same result occurs if I try ‘xhost ‘.

I have verfied that XAUTHORITY is set to the appropriate magic cookie.
I have tried various DISPLAYs including
:0
:0
:0.0
:0.0
:0.0
and the result is always the same.

I have tried this without setting XAUTHORITY and then I get the error that the system is unable to connect to the display.

Does anyone know what I am missing?