We're using a latitude/longitude database put together by the US government. It has over 2 million populated places in it, and for the most part it's fairly accurate. But not always. During testing, I kept seeing cities showing up in places they really didn't belong. And strange things, like Fiji showing up as 'in view' no matter where in the world we were looking.
Digging around in the data, I managed to find a dozen or so mistakes, usually where a longitude of -97.115 would end up as 97.115 or 9.7115. Luckily, most were tiny villages that could simply be plucked off the map and never missed. We also had to deal with countries like Russia, which are far enough North that they actually span most of the globe.
Anyway, most of it is fixed now. Though just yesterday I got an email wondering why 'Centering' on New Zealand would show you a blowup of the Indian Ocean. Slowly, slowly, it's all starting to come together.