AEG 1261 washing machine tries to spin throughout the whole cycle?

My AEG OKO Lavamat 1261 Turbo Sensortronic washer-drier (pauses for breathe) tries to spin inappropriately throughout the entire cycle i.e. even when water in the drum.
A repairman charged me £70 about 3 months ago to fumble under the unit and allegedly 'tighten up a screw which loosens on the spin controller'. It worked for a while and then went back to its bad behaviour.
I have looked under the machine but cannot work out what the repair guy was doing, though he was definitely fumbling in the area of the motor.
It appears that there is something telling the motor to spin at the wrong times, but I don't know what that thing is to try and replace it.
Have a mountain of washing and a credit-crunch bank account - any hints gratefully received.