I just went to my Kobo account and removed from my library any books I had not purchased yet (other than the freebies that came with the Vox). Refreshed my Vox library and all the previews disappeared, except for book #3 with the problem. I bookmarked that one in my account library, refreshed the Vox library, and the pink banner is gone.
I would advise anyone when they make purchases from Kobo to download the file to a computer hard drive. You can do that if you have Adobe Digital Editions. (I use my Sony Reader library software simply because it came with my Sony reader and have been transferring my Kobo purchases to my Sony reader as well...because I like to have a backup.

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