you must have something affecting the burning of the appliance and the ironising probe is shutting it down make sure the there is nothing in the way of the vents on the bottom of the dryer and it is clean around it to allow air for combustion
You say the ignition is working so it can be solinoids but unlikely if it lights occasionally so or electronic ignition control unit faulty heat sensors or the flame retention device ie Ironising probe or you have clutter around the base of the unit
carl A beebee
December 2009