[root@chaos ~]# echo $DISPLAY
localhost:10.0
[root@chaos ~]# gedit &
[1] 2657
[root@chaos ~]# # Works
[1]+  Done                    gedit
[root@chaos ~]#

[root@derob ~]# echo $DISPLAY
localhost:10.0
[root@derob ~]# gedit
cannot open display: (null)
Run 'gedit --help' to see a full list of available command line options.
[root@derob ~]#
[root@derob ~]#