Child object won't follow parent exactly

So, I have a rigged character and i parented it to a box that moves. They move forward together perfectly, but when I have the box turn, the character leaves the box and rotates slower or something because he goes off to the side and then meets up with the box perfectly after a 360, but then leaves again if it rotates anywhere other thatn exactly straight forward. Any help would be great. Here is the file if it helps. Thank you a bunch if you can fix it.


waterflow.blend (998 KB)

The Game Engine really likes objects to be uniformly scaled (preferably 1,1,1). Your cube is scaled 1.2, 4.7, 4.5 and blender gets confused.
Select your cube and apply the scale to it (ctrl+a) so it will keep the same shape, but have a scale of 1,1,1.

Thank you thank you thank you. It works great now.