Per the Saints website:
CAREER TRANSACTIONS – Signed to six-year contract with Saints, (UFA), 3/16/06; Re-signed by San Diego Chargers to one-year contract as Franchise Player, 3/4/05; Designated Franchise Player by San Diego, 2/22/05; Selected by San Diego in the second round (32nd overall) of 2001 NFL Draft.
So he was franchised for a year but signed as an Unrestricted Free Agent the year after that.