I'll do you one better. My 97 E320 also shows defective bulb intermittently, but I have on occasion have my left and sometimes right hazzard lights go out. However, when I re-enter the car later on, the bulb will be working. This is probablly due to some dirty contacts but a real pain in the ass.

David,
Did your friend say if the dealership told him why the cluster had to be replaced or what the problem was? I'm not trilled about having original parts replace by the dealership because it has been my experience that it's never the same afterwards.