I work for a large cable Internet provider and I provision modems all the time. ;)
Same here. Larry, where ever that cable modem mac is registered under is the account holder. Apparently in the past you weren't the account holder or it would have been moved. Nevertheless, you will want a DOCSIS 2.0 modem (Google 'docsis' and click on CableLabs).
Don't buy a motorola surf board. Trust me on that. Buy a D-Link. They work best on cable operators' networks and mesh well with the CMTS.
And it's best to own your cable modem, not your cable box. My ISP/Employer only contracts with 2 manufacurers of cable modems that I don't recommend anyway. They're all around $60 anyway.
Dlink - DCM-202 I might add. Any ?'s