Reading the problems and advice on these forums is both painful and comical. We have grown people who have bought and paid for hardware and books literally begging some guy from Adobe to reset their activations and fawning over him when he does.
Adobe really should be ashamed of themselves. Their software and their customer care and support is appalling. The only thing that seems to work for most people is the handing over of their hard earned cash. The fair exchange of goods and their enjoyment does not follow automatically.
I do so sympathise with you and I can only say that the best advice is to cut your losses, ditch Adobe Digital Nightmare and buy a Kindle from Amazon. I did. It works. It's a joy to use. Authorisations and deauthorisations are a doddle and are done from your Amazon account. Hit them where it hurts - in their pocket. Also suggest you email the ebook sellers and tell them your problems with Adobe Digital Nightmare and cite this as the reason you are abandoning their store.
I still have my Sony Reader and use it to read Gutenberg books and documents of my own. I use Calibre software to do the synching and it works beautifully. if I want to buy a commercial title I will stick with Amazon or eReader. The latter can be used on everything from an iPhone (Kindle software available for this), a Palm device to a Windows Mobile device with very simple authorisation.
Sorry for your problems. You are not alone.
Sorry for you problems, however I'll stick with the Sony reader.
As you now know Amazon recently had a "disagreement" with a publisher over pricing and they pulled people's access to the books they purchased on the Amazon bookshelf. I like being able to download books to my computer and offloading them to SD memory cards where they are safe. I never have to worry about accessing a book I've already purchased.
Sorry for your problems, too and I wish you well. I will also keep my
Sony Reader, but only for non DRM titles. All the best.