There is always the possibility of such failures, but I would not bother with that too much. Many people have bought this lens and I have read about this particular problem only twice until now. This is a more general problem which relates more to the internet than real problems. People don't write about not having any problems, but report even minor problems rather quickly. The result is, that we see some people having problems, but overestimate that easily, since we don't have any clue how much people are really affected. Problems of only few people are being raised to big problems concerning the manufacturer.