We're not used to thinking of them this way. But many advanced military weapons are essentially robotic -- picking targets out automatically, slewing into position, and waiting only for a human to pull the trigger. Most of the time. Once in a while, though, these machines start firing mysteriously on their own. The South African National Defence Force "is probing whether a software glitch led to an antiaircraft cannon malfunction that killed nine soldiers and seriously injured 14 others during a shooting exercise on Friday." SA National Defence Force spokesman brigadier general Kwena Mangope says the cause of the malfunction...