Command Controller Shuffle on Reboot
When you exit and re-launch the game with 4 xbox controllers connected the 'master' controller will switch from player 1 to player 4 typically. (sometimes player 2 or 3 though). You will have to use the player 3 or 4 controller to configure player 1, this is especially annoying if you don't have friends over and want to play alone without unplugging controllers. Removing and adding controllers does not always fix. The only sure-fix I was able to come up with was either to reboot the PC or exit the game, disconnect 3 controllers, launch the game, then reconnect 2 3 and 4.
This MIGHT be on windows rather then SRB2K but it may be something that can be fixed through SRB2K by allowing all controllers to control the game as an option. It would be nice if each player in split screen could at a minimum choose a character on their own, but now I am getting away from the bug and into a request so I digress.