Droppable containers not responding to draggable elements

Hello I'm in a situation where the user can Drag and Drop in a calendar situation. If the user takes something off of the calender I replace the spaces with new dropable divs; they have the same scope as the other draggable + dropable elements, but you cannot drop anything onto them. There's no e开发者_开发问答rrors, it just reverts as if you dropped them onto a incompatible element.