Okay I worked it out. The problem was the user id I was using. I think it's one I've used before so there were password synchronisation problems. I deleted the .gccg folder from my C drive and restarted GCCG. It prompted me for a new user id for which I settled on Gnoll and the connection to the server then worked fine.
Good to know somebody is using that file It should work also with old .gccg folder. Just edit metw.bat file and change the name of user "Windows"-> to your old name.