Glad it's working for you now! Enjoy your new T1!
I'm a Mac user (MBP with OS X 10.5.8). Interesting, maybe there is a bug in the Reader for Mac software. When I go to my account page, it does not give me the option to deauthorize either my computer or my T1 like it does in the old Reader Library software. It only lets me rename them. Maybe that's why you didn't see an authorization option either? Very odd. I never noticed before because I registered my T1 wirelessly.
Other than this quirk that you have discovered, my T1 works fine with the new Sony software to transfer books and sync collections.