Called and hung up as I was about to answer. Am getting more and more of these, glad for websites like this. I suspect they are trying to verify if you have a live number so they can call you later. Maybe doing a service for mass-call lists. Just speculating though.
I was expecting an international call, so even though I didn't recognize the number, I went to answer it. It disconnected before I answered. And I'm on the do-not-call list also.