Tornado 100 Duplomatic turret and parameter problem

Hi
I have an early Tornado 100 (94) with the electrically locking Duplomatic turret and air drawbar. On occasions the turret fails to lock during a toolchange, the solenoid bolt seems to miss the slot leaving the turret free to rotate, I've got a data sheet from the 600 group showing how to adjust this and this has made things better but it still miss on occasions.
The biggest problem is that when it miss indexes the turret light comes on but the control continues to run the entire tool cycle before feed holding at the end of that cycle. You can imagine what happened to my parting tool when parting off hex parts. Why on earth doesn't it feedhold immediately? Can I change a parameter to correct this and has anyone managed to get the turrets 100% reliable.
Any help much appreciated
Thanks
Phil