Yep, it's a sensor thing! there's a steel band around the outside of the drum. (remove top cover to see). This band is connected to the internal sensors on the fins of the drum (metal strips inside of the drum on the fins). There is a carbon brush assembly on top of the drum which is uppermost when the top cover is removed, which, if worn, or worn so badly the spring pushes it out, there is no connection from the drum sensors to the circuit board, therefore the machine believes the clothes to be dry, and therefore stops. (That's if a machine is capable of believing)! A new brush assembly is required. Part No 421307845023. Replaced mine today cost £3-50. Probably get it even cheaper online. Works fine now. Hope this avoids a call out for someone.
Gazzahandy, February 2008