node add/edit creates its own page - not use main page content

First, I'm using D7, PE 1.0-rc1. Site template says "-- let the system choose --". I suspect this is a user misunderstanding. Here's my problem:

I'm overriding the node add/edit form. And have set up a simple one column panel with only field:body added. When I click on the add content link I'm brought to a brand new page .../node/add/content_name. My header, as defined by the sample variant (aka default site template) and sidebars disappear. I see just the field:body only. Instead, I want that form to show in the "main page content" as defined by my sample variant keeping intact the header and other stuff in my sample variant.

I've tried setting the template to be "sample variant" to force the use of that but to no avail.

In the case of my user profile template that I've overridden, when I click on a user profile it places it within the main content section. It doesn't create it's own page but plays nicely with my sample variant, retaining the header, sidebars etc.

Any idea?