beowulf573, you should not need to create a new account. You have two options to register your T1.
One option is via Wi-fi. Click on the Reader Store icon on the home screen. It should prompt you to create a new account or use an existing account. Login with the same email address and password that you used to access your account in the Reader for Mac software.
Another option is via USB cable. Here are instructions from the Sony website. Also, when you attached the T1, select the icon on the screen for data transfer so that the Sony software recognizes it.
http://ebooks.custhelp.com/app/answers/detail/a_id/91