Your original passcode only works once. When you register a product via the link provided in e-mail receipt, you are sent an email reply from "email@example.com" which contains your ilok code, and permanent login information for access to your user account at the link below... Slate User Account
Please check your spam/trash folders to make sure it wasn't sent there.
Also, please add these 3 email addresses to your address book or to your "allowed emails" section in your email account:
This way, our email confirmations, updates, and newsletters will not be sent to your spam/trash folders or be blocked completely.