I just fixed the problem.
The problem was that my Windows Regional and Language Options was set to Japanese (I need it in order to play Japanese games). I switched it to English (United States) and rebooted, and the game worked fine.
I highly recommend putting this info on a sticky, as I'm sure there are other people with the same issue.
Kinda sucks though that I'll have to switch between both languages every time I want to play/quit UFO
