A few weeks ago, I implored my colleagues to maintain the distinction between "uninterested" and "disinterested" after a couple of instances of us mixing them up. You know the difference. "Uninterested" means not interested. "Disinterested" means impartial.
People say "I am completely disinterested in Celebrity Big Brother" when they mean they are uninterested. Disinterested would mean they held no shares in the production company.