Pooba, I was able to duplicate the bug by following your instructions. The strange thing is that it doesn’t occur until after you parent the cube, then move the parent. I’m going to play around with a little more to see if I can find the trouble, but I’d say go ahead and submit it on malCanDo’s bug thread with the same setup description you posted here. BTW, as mentioned, your .blend is Error: 404.
It’s also weird that it requires a collision sensor on the object. If you remove that the bug just goes away. Maybe i’ll just work around and use a touch sensor instead… oh yay, now i just tested that and it does the same thing. Joy, Joy, Joy…