I have a second gmail account (in the olden days that's what they recommended on http://code.google.com/apis/gadgets/docs/publish.html - I see now that they have switched to using filters), and this didn't happen to me.
Are you sure you didn't use the first gmail account to send an invitation? Because in that case it does add the address to both accounts address books.
Are you sure you didn't use the first gmail account to send an invitation? Because in that case it does add the address to both accounts address books.