I've got the same problem. Can't slide objects in the portal. I'm stuck to one and one order line.
For a year I've used my home made invoice system.
(Sure this is complex. And when my native language is not english, it takes time to learn the terms.)
I can't see how to make a print layout without using a portal.
A list layout is not useable because all the fields I have to use in the head and bottom.
Norwegian invoice contains a transfer form in the lower part and shall contain
name and address of the customer and term of payment and so on.
Have I to admit that my problem is unsolvable? Or do the v7 make it better?