Why don't controllers function if they're turned on after a game starts?

[borg101]

This isn't a big issue, but I'm curious as to why most games will not recognize my Wireless Xbox 360 controller after it has power cycled or if they're turned on after most games are loaded. I say most, because this doesn't really happen in Steam games, but it does in most non Steam titles I can think of that I have. It is the most bothersome when I have to change batteries in my controller and the game no longer recognizes the controller afterward. I have to exit the game, then restart with the controller on. This has happened in every single distro, so I'm guessing its a problem with the way Linux handles controllers, or perhaps its just my controllers, 4 wireless xbox 360 controllers.

Is there a reason this happens? Is there any fix for it? Like I said, its not a big deal. Just saves a minute here or there and a bit of a headache.

Thanks in advance!