I had the same problem, my server is at US and I'm in Guatemala, I've installed all the rpms required for X and then followed the info that Jun give here:
http://ccm.redhat.com/bboard-archive/webdb/000J3d.htmlfirst try to open something like an xterm or emacs or netscape in from your remote server in your local machine, in that way you can see that X through SSH works.