The power supply could indeed be the cause. But what bothers me is that, as you say, other games work fine for you, which makes me seriously doubt that it's the power supply. So, what could it be then? Honestly, I don't know... As always, I'll suggest reinstalling the game, even though the chances are small that it will help... Next, I recommend trying to install the game on a friend's computer and see how it runs there. If everything works perfectly, then it's clear that the problem lies with your computer or your system.