Yeah, it's not like it happens all of the time but off and on one will see these things. Yet one person that mounts a scope once or twice a year probably won't have any problems cause the odds are in their favor.

However, at the store we mount 10 - 30 scopes a day and I get to see a lot of the quality control problems with different manufacturers of various items, as others here do as well, and lately Leupold has had far more than its share of quality problems concerning their scope mountings.