I really, really need to start being more careful about examining cartons to make sure that they haven't been opened before. If I'll spend time inspecting a six dollar board for badly-placed knots, cracks, and bad corners, you'd think I would automatically look over the box for a ten dollar light fixture.
You know, it may not even be the stores' fault. Some witless knob may have simply returned the bad parts without ever saying "I think they're bad". Or, some wanker behind the returns counter decided it was less hassle for them to just tape the box up and send it back for restocking. Once, it was fie on them. We have now arrived at fie on me.