electric shock from diplomat ACA9102 dishwasher?

Nobody can tell you why without seeing it. I strongly suggest that you switch the power off at the wall & call in a service company from the shop where you bought it from. It is dangerous to continue using it and needs to be repaired. Also, you should be asking why it has not tripped a circuit breaker or blown a fuse if power is getting to the supposedly earthed metal parts of the cabinet.

Lincoln Appliance NZ
August 2009