I can tell you, and I posted this before Infinity went down for a week. I don't know why it happens but I know how to create the error so Vyn can fix it. Thanks for bringing it back up, I almost forgot about this little error.
When you throw your air one handed hadouken, the one that travels diagonally to the ground (QCB+P) when that hadouken makes contact with any projectile that the enemy throws, it nulls all of your hadouken powers for the whole round. I'm not sure if Vyn knows about it, but also I'm not sure where to post this so he can see it