Make sure that the 'repeat event while actor is colliding' option is set to YES on the collision events. There was a bug in older versions where this would be set to yes by default even when it said it was off, in the latest version it works perfectly correctly, so any old games you load in to the new editor where your platform\repeated collisions dont work it's probebly because of this. I remember at the time it caught a few people out, myself included