Of course, my localizationKey is defined both in french and english and I exported my XML files.
Yep, I suspected you did... I was just trying to think of something that could have been missed. I usually forget to generate the XMLs after creating a new key.
I have tried to duplicate the problem, but haven't been successful. One thing I noticed on your print screens is that your control is applying Full ThemeSupport, but then the picture doesn't seem to show this characteristic. Once again, just thinking of something to check, you don't set the Title programaticaly anywhere, right?