This can be attributed to the gauntlet of tests that are required to certify something "mispec", plus the time it takes from that point to when it's been engineered and fitted into the planes/ships/etc.The military is not as high tech as portrayed in the media. I'm not sure about the USAF, but certainly here technologies are far behind those in civilian hands.
They mentioned one flight coming into tampa that accidentally landed at MacDill instead of TIA, but thats an honest mistake, the airports are nearly the same size, and are about 3 miles from each other. This was in early 80's I think.I guess it happens all the time.
http://www.thirdamendment.com/wrongway.html