Actually,lefts and rights are usually caused by a draw length that is too short.What happens is the elbow on the release hand doesn't get extended straight back and the result is lefts and rights.With fingers and a whisker buisket the results could be extreme.

Also ,if the draw measures the same as you have always shot.I would look at center shot.If you are paper tuning to get a bullet hole and to get the bullet hole perfect you adjust center shot off,the result will be lefts and rights.This is a result of tuning to your torque of the bow or tuning to the wrong spine arrow.

The reason you see lefts and rights on a bow that the center shot isn't correct is because if the arrow is pointing to the left(right handed shooter).You end up pulling the bow across your body from left to right to sight it in,the result is that your body and bow are no longer in a straight line with the target and it is very difficult to hold the bow on target and you start drifting from left to right and back.Therfore the arrow is hitting in a straight line but is following your movement.


Hope you find the answer in here some where.It is really hard to diagnose problems over the net.