Check your image point on every single frame. Sometimes when i insert an animation, mostly explosions, the image point is off by a few pixels. Even if you use the image point > bottom or whatever, it can be off because of your frame.
Try slowing down the whole animation, 1 or 2 seconds, and then slow down each frame also. Run it. Watch the animation. I've spent a bit of time trying to get it exactly right at times.
Save your project before you attempt this, but not during. So you can go back to the original in case things get too far off.