1) Plug in a joystick
2) Launch the game
3) Follow this path: Options > Controls > Weapons
4) Select "Fire" command
5) Set fire command to any Joystick button
6) Save and close the new setting
7) Shutdown the game
8) Unplug the Joystick
9) Launch the game
10) Follow this path: Options > Controls > Weapons
11) Observe Joystick control missing from "Fire" button