Toggle between views by double clicking a issue (Card) is not working

In GreenHopper 4.4, both on Planning Board and Task Board, if we mouse hover on a issue (Card), mouse pointer changes to double ended arrow. Then, if we double click on the issue, current view of that issue is changed to Card view and vice versa.

It is a very useful feature. But this feature is not working in GreenHopper 5.1.

We appreciate, if you make this feature back to work.