Object reverts back to standard size when i move its parented layer? (video included)

[Romanpen]

Hey guys, I was using the parenting tool to make a puppet for my latest movie when I noticed that the object on one layer ( a layer for the back of a characters hair) would revert back to its large size whenever I moved the object on its parented layer that its connected to. Any Idea how to fix this? 

Here's a video if what I say isn't making sense. 

[Romanpen]

So just a few hours after i put up this post i realised i could solve the problem by putting a keyframe in line with the keyframe that starts with the hair. In the video you can see that the layer  in the timeline that holds the head goes all the way back to the beginning, I cut everything up until the start of the back-hair object......idk why though?

[Nicktendo28]

Glad you were able to solve it and share it.