Can you use 1 form to save an object and that object's attachment?. All
Yes. In addition to the mandatory fields that aaa needs you can define as many additional fields, validations etc to your model. SO you can have DVD and DVD attachment in the same form.
I have other issues with this plugin, but I thought I'd start here. (for instance, I've specified file_system_path => 'public/files' and it is still looking for the db_files table...)
Do you also have :storage => :file_system specified?