This isn't my post, I copied it from the Steam forums. Not long ago I posted on this forum about how messed up my Xbox360 controller was in the game, well here's a fix for people having the same issue of buttons being reversed, (E.g. B is A, X is B, Back and Start).
"Many people, me including, have been experiencing weird button configurations with the supposedly officially supported Xbox 360 controllers in Super Meat Boy.
E.g. B is A, X is B, Back and Start are the shoulder buttons, Right stick click is Start and so on. Completely bonkers. Messing up with the buttonmap.cfg doesn't seem to help much.
Well, I found a fix that works at least for me in Windows 7.
Go to My Computer, System Settings and then to Device Management. There deactivate the HID Compliant Game Controller (or something along those lines, I'm on a Finnish language settings).
The Xbox 360 gamepad should still work just fine, although the center light goes off, and the controls in Super Meat Boy will be back to what they should be.
After playing it's advisable to turn the HID Compliant Game Controller back to active. Although I think it'll reset automatically on system reboot.
(The first Dark Souls had the same weird button config problem too, and this same trick worked for it also.)"
Source: https://steamcommunity.com/app/40800/discussions/0/617319460970495569/
"Many people, me including, have been experiencing weird button configurations with the supposedly officially supported Xbox 360 controllers in Super Meat Boy.
E.g. B is A, X is B, Back and Start are the shoulder buttons, Right stick click is Start and so on. Completely bonkers. Messing up with the buttonmap.cfg doesn't seem to help much.
Well, I found a fix that works at least for me in Windows 7.
Go to My Computer, System Settings and then to Device Management. There deactivate the HID Compliant Game Controller (or something along those lines, I'm on a Finnish language settings).
The Xbox 360 gamepad should still work just fine, although the center light goes off, and the controls in Super Meat Boy will be back to what they should be.
After playing it's advisable to turn the HID Compliant Game Controller back to active. Although I think it'll reset automatically on system reboot.
(The first Dark Souls had the same weird button config problem too, and this same trick worked for it also.)"
Source: https://steamcommunity.com/app/40800/discussions/0/617319460970495569/