I see that you are using a 5D mk II.
Die 5D mk II and the original 5D had only one reliable focus-point: The middle one. All your 5D mk II shots are off-center composed, so that I assume, you uses Servo-Mode on an off-center focus point, which will not work very well.
All your 1000D are center-composed, so you used the center point (which is the best focus point normally in all cameras).
Oh, and for action shots: Activate the center focus point extension on the 5D (adds 6 more invisible focus points for focus tracking). Then the 5D is very well capable of tracking fast moving subjects.