With Piwik 1.2.1 in French, there's a bug with a submenu string: "Pages d'entre" is displayed "Pages d'entre". See the attached screenshot.
I've just found that this bug also concerns other strings containing an apostrophe, because the submenu "Vue d'ensemble" is displayed "Vue d'ensemble".
This is fixed in trunk. (Translation strings are now html_entity_decode()'d.)
Marking as a duplicate of #2202.