Had the same issue. On-line chat trying to reset my password resulted in a "new ADE account" as they are unable to provide a reasonable way to reset the password so that you can update the e-mail address.
When you authorize your e-reader with a "new DRM" the e-books are still linked to the "old DRM".
Now the majority of my library is inaccessible as the defunct EMAIL ADDRESS and therefore the "old" DRM code is ATTACHED to the e-book.
Will be happy when ADE goes the way of the dinosaur.