Pop Goes The Breaker

Bob and Monika are still having problems with the new microwave.  It works when it feels like it.  Else it just pops the circuit breaker.  Saturday morning Monika heated up her waffles in it with no problem, then about five minutes later Bob went to heat his up and the breaker popped again so he had to use the toaster.  Luckily he doesn't butter his before he puts it in the microwave like Monika does.  They put in a maintenance report with the Management, no one has come to fix it yet though.