One frequently-overlooked software "tax" is geopolitics. We've alread seen that the time zone and regional settings dialogs created international unrest. It appears that Google Maps failed to recognize the extremely sensitive issue of naming the body of water that lies between Korea and Japan, as well as stirring up international tensions with the way it labelled the island of Taiwan. Like many issues regarding naming, these subjects are tied up in history with strong feelings on both sides. (And Google's efforts to placate the Taiwanese government only served to anger the Chinese government. Welcome to the big time.) As we saw in the time zone example, deferring to United Nations-approved boundaries or terminology is not always sufficient to calm the parties involved in a dispute.
This is why you tend to see the word "region" used in Microsoft products instead of "country". There are still many parts of the world where sovereignty is a highly contentious issue. If you call something a "country", you have effectively "taken sides" in a dispute you probably would be better off staying out of.
Geopolitics wasn't so much of an issue in the past, where you could control where in the world your program was running by virtue of controlling where your distributors are. But with the Internet, everything you post instantly becomes available to an international audience.
Unfortunately, I don't have any good advice on this particular tax. My personal rule is "Stay far, far away from maps."