Karel X, those accidents were due to a rudder problem, not elevator, and the design was modified to sort it, not only the design of the PCU but also in the hydraulic pressure supplied to it.
There was a problem more recently where deicing the aircraft in a certain manner caused a build up of slush on the elevator mechanism inside the tailcone, but there was a very fast change in deicing procedures to deal with that. Details are important in a discussion like this.
