Keyframing constraints overwrite I have a objectA, and when I add a copy location constraint to it to another objectB with influence 0 at frame 10 and then add keyframe. Then on frame 11 I change the influence to 1 and add a keyframe, but when I go back to any frame from 1-10 I find that the influence is 1 as if it overwrote the inserted first keyframe which was inserted when the influence was 0. Any advice please?
To keyframe the influence value of the copy location constraint:


set the influence value to 0
go to the frame before the value should change 
place the mouse cursor on top of the influence slider
press I to insert a keyframe
jump to the next frame in the timeline with →
set the infuence value to 1 and press I again