Connecting via ssh tunnel

Hi,

I have a postgresql server setup on a Solaris 10 box. I can connect to
the db via psql from the local machine. What I have been trying to do
it connect with pgAdmin from my workstation. I have setup the tunnel
correctly, local port 5432 and destination localhost:5432. Everytime I
try to connect I get the following message.

2006-11-24 20:42:48 ERROR  : Error connecting to the server: server
closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.

I havent altered the config files, so postgresql should be listening
on localhost.

Any one got any ideas?

Ben