So I was so excited to open my box and start using my new DC33 (replacing my four year old trusty DC14). I turn it on, and it immediately starts making that loud, high-pitched grinding noise. It won't stop, and nothing is obstructing the beater bar. The DC14 makes this noise on occasion when there is something stuck in the beater bar, or if I hit the vacuum too hard against a piece of furniture. I got the DC33 so that I didn't have to listen to this awful noise again. My carpet is low pile, and already clean from my old Dyson, so I got a lemon. Beyond disappointed. I've never had a problem with refurbs before this.