Constraints glitch?

Hi,

I am currently improving this concept: https://www.youtube.com/watch?v=uV8v33zj6RI
Which was done in element 3D. So i followed a tut on how to make some gears in Blender (since i AM a noob).
but i encountered a glitch (my fault probably)

Also blender just crashed :frowning: without auto save -_-

Anyway, i did record this glitch and uploaded it, if anyone could give me a solution?
You might wanna pause the vid for the text :wink:
the glitch: https://www.youtube.com/watch?v=EkKwGwoZ8AA

So, when the box, or any other non circular object has been linked to the gear it starts to glitch when you turn, so i tried the β€œchild” option, yet the same happens. I am currently using 2.67b, i should probably download the new version :smiley:

Well, i am stupid. why didn’t i just model the gears?