Need to set a min-height for the container <ol>, so that users could drag items to an empty list.

[hy9be]

This issue can be reproduced with your first example "Connected lists with drop animation" on http://johnny.github.io/jquery-sortable/

Please drag all the items of the left column into the right one. You will find there is not way to drag any items back to left from the right column.

[johnny]

Thanks for pointing this out. I fixed the css