Did you use Portfolio to create a document where the items are all embedded inside, rather than combined together?
It looks different, and opening that file in Adobe Reader XI shows a file listing with the icons associated with the file type.
This could be a cover sheet, but I'm not seeing anything that screams ad- I just see the file icons.
I'd like to help you, but it's possible this may be something that depends on the file itself, in which case you're probably better off filing a support ticket so the support team can look at the file itself: https://www.gonitro.com/support/ticket