A very famous case study would be Chevrolet's Nova. When it was launched, they were expecting its Mexican market to purchase a lot of its units. They failed to understand, however, that "Nova" in Spanish translates to "can't move".
I've been seeing a certain ad lately in the Philippines that makes me squirm each time. It's the recent thematic campaign of Whisper Philippines, whose ad you can preview below:
Did you spot (pun intended) which word makes me squirm?
It's the term "back friend". Back friend has some negative connotations, I believe. For one, it could pertain to something sexual--no need to delve into the details on this one. On the other hand, it could connote something like a friend--a back-up friend--and that itself is a place that no one would want to be in.
Thoughts, anyone?