so as of 11 u7 this feature does not work like the support document states. you MUST do it partially backwards from the recommendation in the DOC. the steps for the periodic snapshot creation are correct, but the share MUST be built out with no snapshot selected. then after that you can edit the share, add the snapshot task and restart samba.
i removed the share and tried the entire process 3 times to verify that this worked, and that no other combination was available.