The story behind this has all the makings of a conspiracy theory Hollywood movie. As reported in IEEE Spectrum Online, apparently a scientist stole an electrolyte formula from his employer in Japan and left the company. Shortly afterwards, this scientist took up with a Taiwanese electronics manufacturer and used the formula there, then went on to sell the formula to other firms. The problem was, the formula was wrong.
Missing were a few crucial elements in the chemical concoction that made up the electrolyte inside the capacitor. Without these additives, according to Dennis Zogbi of Passive Component Industry magazine, the capacitor will emit hydrogen gas and burst after a short operational lifetime.