The trick to making that bucking stop lays in your right foot. When you gas it then let off before it shifts, you are teasing the ATX, and it lashes out by "bucking". Now if you accidentally do this again, what you can do is, after you let off the gas and realize "Oh $#it it's gonna buck on me!", ease back on the gas. When you do this, the shift will smooth out a lot more than if you would have let it "buck". Just my personal experience with the issue...
