If in fact the wobble or spin is a genetic defect then in theory all of the Spiders ever produced should have it since the original Spider that Kevin brought in from Africa was the only one ever, to my knowledge, and he spins and wobbles.

Now I'm not saying there is anything wrong with them, it's just their characteristic. Some do it at feeding time but most do it in the middle of the night. Go check on them in the middle of the night and you will see them do some crazy stuff.