I had hoped to swap the cable card from my HD TIVO to my TiVO premier seamlessly, but no such luck. I got the grey screen with Host ID and DATA ID and a number from Time Warner to call for activation. Unfortunately the helpline folks were uneducated about the cable card. I tried three times hoping to get a person who knew what they were doing but they basically read to me from the website and eventually told me I needed a technician appointment. I took the appointment even though I knew it was unnecessary.
Then I did my own digging on the TWC website and found that there is a dedicated help number for cable cards. It is open 8-5 eastern time and the folks who answer the phone only deal with cable cards. Maybe the phone number on my cable card was old because it was from a previous tivo, but for anyone else in the same position, use this number for Time Warner Cable Cards: 1-866-606-5889. You'll save yourself a lot of frustration!
I'm gonna go cancel my tech appt.