add unpublished content to pane As the maintainers of panels are not really reacting, my questions here:

I am creating panel-nodes which should be filled with existing content.  I need to have a preview functionality, so the user can add the panel-node and the unpublished content, review it, and finally publish everything.

as admin (user/1) I can do so without any problems, but other authed user with the permission to add all content-types etc. cannot. 
they can open the dialog add content to pane > exisiting node. they can choose the unpublished node in the autocomplete field.  but after submitting the form (Finish) they get the message "Invalid node". this happens only with the unpublished nodes.

Is that a bug or am I missing something?

update: http://drupal.org/node/1294792
I've never used panels, but it can be a permission problem. As far as I know, to view and publish unpublished content you need to have set the "administer nodes" permission. To let some roles manage certain unpublished content types without granting them more than they needed, once (in D6) I successfully used the view_unpublished and Publish content modules.

Hope it helps.