Crocee,
Try putting it in a cup behind the machine or to the side of it instead. That way you can have it sitting upright the way it wants to be, and it won't wobble on the pin at the same time. Cross wound thread doesn't like to turn with the spool it wants to come off the top of the cone / spool like serger thread. Additionally, if the huge end is up, you're creating a lot of inertia from that end wagging - think of the pendulum on a grandfather clock - and I can see that causing problems.