Sorry that didn't help ~~ try my next stock suggestion ...
There are lots of bugs in ADE2.0. Try replacing ADE2.0 with the older but more reliable v1.7.2.
(You can have them both installed at once if you like.)
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
http://helpx.adobe.com/digital-editions/kb/cant-install-digital-editio ns.html
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172
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- One bug in ADE2.0 is that it doesn't recognize some devices.
- One is that it refuses to work with library books with some devices (including most Sony readers)
- One is that it gets registration/authorization confused ... my first suggestion tried to resolve that one.