When you create shape layers, they are the size of your comp. Check out the position of the layer when you start, it will be at half the width/height of the comp. And the path position of the shape layer isn't the comp position, but it's based on the coordinates of the layer. If you move the shape layer using the transform properties of the layer and not Transform:Shape(under the coordinates) you will get offsets like in your video.
You can create an expression to add the difference, like so for a 1920 x 1080 comp.
value + (thisComp.layer("Shape Layer 1").transform.position - [960,540])
Check out this example project, it illustrates the problem and solution.
9873_shapelayers.aep.zip
For a lot more information on shape layers, check out the tutorials by
Andrew Devis
Johnny Cuevas, Editor
ThinkCK
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.
