Tina,
I can only offer my experience with my Kirby Gen 3. Check for hair wound tightly where the ends of the beater bar attach and turn. It could be wound so tightly you can't see it. I used an exacto knife and was amazed at the hair that came out, preventing it from turning.
Next check for dirt between the beater bar and the belt. Dust can build up and the friction will turn it into something slick. Also hair can build up there as well.
Lastly, check to see if there is a sensor on the inside of the housing, and a corresponding sensor on the beater bar. Make sure both are clean.
I'm sorry I have no experience with Dyson, but I hope I've given you some ideas about possible solutions.
Good luck
Bonnie, December 2008
