Hi,
When in a page, if I understand well, I have a similar problem: when I switch from my default language (french) to the english version, my menus disappear, except the “home” main entry.
I don’t see much under the Menus admin page (particularly, I don’t see entries for the english version of pages or entries with the english titles).
After reading documentation, I see (page 6) how it may be parametered, but I don’t have the “Navigation Label”, “English Navigation Label” in my Appearance / Menus page. Maybe this is what ristjaq was able to find to help him, but it seems I miss this.
Any help appreciated…