Display X11 application from another machine

Having a problem running an X application on one machine to be displaied on another machine.

Here is the set up. I have two machines, A and B. Machine A is 10.04 LTS and B is 11.10. I am logged into machine A and have a telnet session on machine A connecting to B.

On machine A I run "xhost +" and receive the response "access control disabled, clients can connect from any host". In the telnet session of machine B I set my DISPLAY variable: "export DISPLAY=A:0.0" and then run a command (i.e. xlogo) and get this error: "Error: Can't open display: A:0.0".

I come from the days of Sun Workstations with X/Motif and this was how we used to do it back then. How would it be done in Ubuntu?

Oh, /etc/hosts on both machines have the entries for both and they are on the same LAN.