Why These Extra Lines on Corkboard?

I’ve chosen to “Open with all subdocuments” on the corkboard, and I would like to know why I’m getting these five blank areas:

Usually I get this kind of result:

Thanks!

Because you have empty folders and have some setting for the corkboard to show folder content below? You have five folders and five empty lines.

Yes, you are displaying stacked corkboards, some of which are empty. See section 8.2.8 of the manual.

Thanks, Lunk. That seems to have solved it, but I’m not sure why. I put something in just one of the folders, and now all is okay.

Still don’t understand why that would fix it.