Yes, I use correct Sony updater and the Reader appears in Device Manager. Please take a look onto the screenshot I made right now:
http://tomxx.net/SR_problem.jpg
It shows that greyed out Update button (number 1.0.01.07170 comes from my different tries to cheat an Updater, it's the most up to date Sony version) and an Error (instead of the Reader) displayed by eBook Library. Item is recognize in my OS, however I might try to launch in under different WinXP.
I agree, I need to make it visible for the updator, somehow..
I didn't install anything like Sony USB driver but hope that it goes with eBook Library together. In my Add or Remove Programs I do have just 'Ebook Library by Sony', nothing else.