When I worked full time as game developer some years ago I learned quite quickly that the most problematic issues with computer games are graphic drivers: Some of them are buggy, and a small percentage of your customers will come back to you and blame your game for creating blue screens, randomly restarting their PC and other nasty behaviors. The game developer is completely innocent in this case, the reason for this is usually an error in the 3d graphics driver. But explain this to the customer: Quite difficult.
Today, the situation is a bit better, because apparently the quality of the graphic drivers and the operating system using it has improved (for example Windows 7 will no longer crash when its graphics driver does), but these issues still are there. But I also now have learned that this problem is not only limited to graphic drivers: Since I developed the audio library irrKlang
and a lot of games are now using it, from time to time gamers report that when starting up the game using irrklang weired stuff happens: For example the screen becomes dark or mouse input stops, things which a sound library has no influence over, honestly.
Again, the reason for this is not irrKlang but a buggy hardware driver. Fortunately, these effects only happen in very, very, very rare cases, and since irrKlang supports multiple audio drivers it is possible to circumvent these, but it really makes me think that it must be quite difficult to write working hardware drivers. Or maybe these companies are simply hiring weird programmers.