Well, it's glad to hear I'm not the only one with this AI servo issues. Loaded your camera config and magically the focus was spot on! I still have issues with AI servo failed to focus even on midday, the AF just stayed there like it was off, but the indicator says the AF is still on. Tried to track a person walking away from the camera (in mid-day, lots of lights and contrast) and it fails to track! I just can't believe it... The AF settings were "Case 1", AF points were automatic, and left everything else default. The AF engaged when I pressed the shutter button, and it took 1st frame spot on focus, but the rest of my burst were all OOF. I'm guessing there's a problem with the AUTO AF, it worked out fine with ASSIGNED AF points though. Quite a shocking discovery that day. Btw I'm using a 24-70 f/2.8L lens.