but thats just my point; its not old, we live in an area with NO humidity, it was kept inside the car...
it shouldn't have any form of wear/tear, other than previous use
Left in the car all year long? Then it just be the way metal normally acts with changing temperature metal doesn't play nice with seasons every time it goes from winter to summer the metal takes a beaten.
Or it could've been defected as in there was defects in the mold causing the sockets to be doomed before it was even bought.
Anyways it could be for any reasons like something like when you used it in the winter some water got inside micro cracks then frozen and unfroze which makes cracks bigger once metal has become "compromised" its a pretty useless.