Droppable - hoverClass Problem

Droppable - hoverClass Problem

Hi!

See the fiddle!

When I drag the Container 4 to a droppable div (.container)  the hoverClass works as excepted.

However when I drag the Container 3 (with the Container 4 inside) the hoverClass doesn't work, but if I drop in red zone, the drop is accepted.

So what must I do activate the hoverClass when I have a drag with drag and drop?

Thanks  in advance!