jQuery UI Sortalbe seems to like List Items, but not Tables?

I’ve created two sortable grids as a test, one uses a table and the other uses lists.

Here’s the grid that uses a table: http://www.search-this.com/examples/test/drag-n-drop1.htm

Here’s the grid the uses a list: http://www.search-this.com/examples/test/drag-n-drop2.htm

The code is pretty equivalent if you scrutinize it.

But if you play with each grid by dragging and dropping (on the gray bar on top of the cell) it becomes apparent that the one comprised of lists works better than the table one. Why is that?

Try dragging cell 1, via means of clicking on the gray bar, and dragging it the right of cell 4. Not easy to do in the table grid. Not too tough in the list grid.

Am I missing something? Should they not perform the same?