Sorry I wasn't very clear in my original post, I don't have the umlaut on my keyboard here, but I did spell it correctly then, dative and all. Just seemed they didn't accept the word as a translation of restaurant. In my experience Gaststaette and Restaurant are not entirely synonymous. A Restaurant to me is more upmarket, possibly themed, and most likely in a city, whilst a Gaststaette can be your local neighbourhood place, or rural, or just not so fancy shmancy. But this might be an east german-west german distinction, every Restaurant is also a Gaststaette here, but not every Gaststaette deserves the name Restaurant, so I used it as the umbrella term. Never mind, you live and you learn...