Delphin, good suggestion to download the latest version of Reader Library. In the past, you did have to manage books and authorizations through ADE and the Sony software separately. With recent versions of Reader Library, Sony has integrated Adobe support into their software (maybe starting at v3.1?). The Sony FAQ page explains that when you install and register the Sony Reader Library, it will create an Adobe ID and password for you if you don't already have one. It can also link to your existing Adobe ID.
http://ebooks.custhelp.com/app/answers/detail/a_id/145
If you have a Mac (like me), ADE doesn't recognize the Sony ereaders. As of January, the latest news on the Adobe forum was that there is still no future plan to incorporate Sony recognition in ADE for Mac. So Mac users have to use Reader Library in order to authorize their ereaders for ADE DRM and transfer library books to the ereader.