+++ This bug was initially created as a clone of Bug #375255 +++ The add-on title for the german locale (/de/) is empty, it exists for en-US (Iobloggo statusbar). Sounds like the fixed bug 375255.
The add-on in question is: https://addons.mozilla.org/de/firefox/addon/3047
Looking at tonight's database dump: The translation fields for German are NULL, so it's not bug 375255 reoccuring.
I found it: The developer chose a default localization of Italian yet he didn't provide any Italian l10n strings. I reset his default l10n to en-US for now, and once he actually translates his add-ons description, he can reset the default value to Italian.