So if I well understand, when editing a page, you can see the correct title of the translation in the languages metabox. Correct?
Could you check that you correctly setup the language switcher? There is an option "Forces link to front page" that you should keep unchecked to obtain what you want.
If everything is ok in your settings, could you try to de-activate all other plugins and switch to a default theme then activate your theme and other plugins one by one to check if it comes from a conflict?
