I am certainly no expert in this field, but I do get a chance to speak to technical experts --- and so I did. According to someone who is qualified to testify in court about such matters, without knowing the specifics, this person would advise never to pass the insulin pump through any x-ray or magnetic device.
The reason he gave was the same one about the full-body scanners. The levels of radiation / energy are given when the technology is functioning properly and well-calibrated. However, there is no procedure in place at the airport to make sure that this is true, and the testing is not done to test the probability of malfunction when operating all day, every day.
Bottom line, normal levels could be safe, but no way to know how often abnormal levels occur because monitoring procedures are not in place.