Drag and drop using xtemplates in a grid

I've created a grid and it has drag and drop functionality which worked fine.

that was until I changed the column to use xtype: 'templatecolumn'

Now if I try to drag and drop it will only work if I drag the row by the area that doesn't have text.

http://ift.tt/1nJQYVB

See the above fiddle which is a slightly modified code example taken from the docs on the ptype - gridviewdragdrop.

So is this expected behaviour and is there a way to get around it? (using Ext JS 4.2.1)

Thanks