ef 24-105mm f4 L - focus is changing as the zoom changes?!

Hi,

I just bought the Canon 5d Mark 3 with the 24-105mm f4 L series zoom lens.

When I zoom out to 24mm and autofocus on an object the resulting focus selected is ALWAYS less than the autofocus resulting on the same object with the zoom set to maximum (105mm).

Is this normal? Is this your experience?

I ask as I am used to zooming up to focus and then zooming out and recomposing the image. I am concerned that the focus is changing as the zoom changes. Not the reading on the focus setting on the lens - only the value that is selected.

Is this your experience with this particular L-series lens?