Hi! 
I'm not sure if I don't understand how the motion keyframe works or it is some kind of a bug. 
Here's the video: https://www.dropbox.com/s/r1mx4vsxfs4pt47/CTA3KeyFrames.mp4?dl=0
As you can see I made a blank space on my timeline so I can copy motion keyframes from different part of the timeline. All the keyframes for all the body parts, before the blank space starts and at the end, are inserted.
You can see that through all the blank space, my character doesn't move. When I copy the keyframes from different place of the timeline to the blank space, it totally changes the bone positions.
In my opinion it shouldn't change at all, since all of the bones have their keyframes in position. Why it happens like that? Am I missing something?