Linked multi sites work only one way

Hi
I’ve installed multisite to run a multilingual version of my site. What I am intending to do is to have replicated subdomains each showing the same info as the primary site but in my chosen languages.
My problem is this – In the primary domain by clicking on My Sites , I see my subdomain – So far only the French version. and I can go to the French subdomain. Once I’m there, though I’m stuck – I can’t go back without entering the URL of the primary site in my browser, which kinda makes a nonsense of having linked sites. The My Sites tool bar vanishes. I guess there’s some authorization box I have to tick somewhere maybe? Anyone know how to do this???
http://www.eclipsesailing.gr and fr.eclipsesailing.gr