Welcome to the Club! Got the same Problem and had a really hard time reaching the Customer Support because they were down due to maitenance! Just wrote to their experts chat and hope to get an answer in this life!
I tried to authorize my Computer and eBookreader with a new Adobe-ID, but it says I've done used this ID too often, even though it was brandnew! Can't copy my just-purchased eBook because "Copying is not allowed".
I hold my thumbs for you that Adobe solves this Problem fast enough. Other ways I'll sell my eBookreader and buy the Kindle-Reader from Amazon and say GOOD BYE to Adobe!