xterm on sles 11.2

I am trying to get xterm to work on sles 11.2. I did it recently on 10.3 and it was really simple but nothing works on 11.2.

On 10.3 I installed xterm on the server and ran xming for windows on my local PC. Then from a putty went to SSH > X11 > Enable X11 forwarding. When I connected to the server I could run xterm and it worked straight away.

However, when I do the same thing on Sles 11.2 and I try and run xterm it says the display isn't set.

Is there something special I need to do for 11.2 to make it work. There isn't any firewalls enabled so this isn't the problem.

Thanks for any help you can provide.

UPDATE I have changed the SSH config files as suggested by twalberg but still no luck.

In /etc/ssh/ssh_config I have the following

Host *
#   ForwardAgent no
   ForwardX11 yes
ForwardX11Trusted yes

In /etc/ssh/sshd_config I have the following

X11Forwarding yes

I then restarted ssh using /etc/init.d/ssh restart and then performed the same steps as mentioned in the question with putty but still getting the display not found

Solution

I've managed to find out the problem. I need to install x-core package in yast. Didn't need to do this in sles 10.3 but apparently for 11.2 you do.

Thanks all for your help and suggestions.