Doh! Your name is Jarkko. Sorry.
<IIRC>
When you have logged in to the remote host I think you should not set DISPLAY manually - ssh and the "-X" will do that for you. If you set it incorrectly it may very well seem to work but the tunnel will be by-passed IIRC. So you might end up sending passwords in the clear.
</IIRC>
