When the paddle on my machine has stopped rotating...

The motor and guard on my machine fit quite loosely and when the ice cream reaches the consistency where the paddle can no longer rotate it immediately shoots the motor off the top of the machine and the guard seperates from the motor. This is quite scarey and does not seem right to me. I have spoken to someone at Magimix who was cagey but said this was not the first time they had heard of this problem. In desperation i have ordered a new motor and guard but am worried this will happen again. Anyone else heard of this happening?