maybe, you end with the wrong image, i have had the same problem ewith 3d if i make something spin....i turns like 360 degrees but the begin maybe the same as the end but the probgramm sees that the beginn i at 0 and the end at 360....so it "jerks" back to 0...so im doing my animation in maya and then make it work in unlead gif animator, a very cheap prog but quite handy just paste in hte images and click make .gif,
but i tried this tut and get the same problem, so it not only you