I cannot start X-apps on my Origin from my Octane

Hi again,

I can login graphically from my PC to my Origin using 
X-Win32, but I cannot login graphically from my Octane 
to my Origin. The reason is to test some X-apps with 
OGL/DGL and I can't do that with the PC.

Text terminal works fine on Octane, but when I try to 
start any X-app I get

Xlib:connection ... refused by server
Xlib:Client is not authorized to connect to server
Error: Can't open display x.x.x.x:0

Any hints on what to do? I've read a some on the internet 
but not managed to solve the problem myself.

regards
  Bjorn