You have got that sprocket adjusted very well...I would recommend the same thing that others have already noticed though, and that is having the wheel itself "trued"...That is spokes being adjusted so that the rim itself also does not wobble...If your not knowledgeable as to how to do this, bring it to a bicycle shop to do it for you, ( It usually does not cost much), (That is a new rim like i mentioned to you in previous posts, Right?)...lol... and then just put it back on that truing stand mechanism that you used to align the sprocket and see that it all runs true and stable when you get it back from the bike shop...That should do it for you...DAMIEN