I assume you have gone through all the step of authorizing ADE, and then authorizing the device?
Can you read the book on ADE itself?
Does this happen for all DRM books or just for one/some?
When I had a Bookeen Opus ereader I found that a small proportion of books would not work on it;
some just would not open, and sometimes trying to read them would even crash the ereader.
I haven't had a similar issue with my Sony PRS-350.
