Homepage – Switching between languages

Hi,

On any page, I can switch between different languages (ES or EN/GB) of the same page. But on the homepage then it will only allow me to switch to ES but not back to the default language EN/GB. Looking at the URL that appears in bottom left of browser window for the button all seems OK. I have cleared the cache of the browser and all cookies but no better.

Any ideas?

Regards
Billy