Xsession dont open screen remotely being RHEL5

[Daniel Romeo]

Estimated co-time-keepers!
Habitually I connect in my workstation running RHEL3AS to a Server  
running  RHEL3AS (ssh way).. and remotely run
one Xsession to get a remote graphic session from the Server, and Its 
all right...But when I connect from another workstation running RHEL5 
server, the remote graphic session execute but doesnt show me the remote 
screen.:

[root at yumserver xdm]# ./Xsession
message in /root/.xsession-errors is :
xsetroot:  unable to open display ''
xrdb: Can't open display ''
xrdb: Can't open display ''
xmodmap:  unable to open display ''
/usr/X11R6/bin/xmbind:  Can't open display

(gnome-session:2081): Gtk-WARNING **: cannot open display:

Any idea?
Greetings, Daniel