problem with Multilingual plugin

Hello again, I have installed the WPML Multilingual CMS plugin and set the language switcher into the menu bar. It seems to be working but I can't choose a different language. If I place it in the top header sidebar is working. What can I do to maka it work? In my site I have now booth ways for you to see:  http://www.astypalaiacamping.gr Thank you in advance Armandos