Strange Bug in the D&D Column size, inside a saved section

[Gabrisan]

Hi there, 

I think that I found a bug in the SECTION (saved section)

I've replicate this bug in the Boilerplate CMS, so I think that it's an editor problem. 

If you try to set a width on the column inside a d&d section, the editor will create the correct column width at first but, if you try to split it, the editor will clone the column with the correct span, but it set the first column as SPAN1 class, and you cannot be able to drag the column.
This it could resolve with some drag, but it could be painful for an editor without experience or a client.

Here some screen.

This is the boilerplate d&d section that call the card module.
I've just set the widht=6.

And here the result at first view

If you try to split the column

As you can see, after the split, the first column becomes a span1 column.

Hope that someone could help us.
Thanks!