360 gamepad button stops working in online match

Hoping someone might have an idea here. I have a brand new xbox 360 wired controller that works perfectly. In SSFIVAE right after I hit “ready”, about half the time, the bumper button that I have assigned to light punch and also “start/advance” etc stops working. If I cont/alt/del it works fine, its only in the game. After minimizing then maximizing the game, it will work again, but usually only for a short time. Any ideas on this? Its only happening in this game, no problems at all anywhere else.