I am wondering if the fruit is slightly different where it grows naturally? So the seeds are softer? (As with mangos, the skin is eaten in some countries but is quite tough when the fruit gets here, though I shouldn't think anyone would eat the huge stone)
click here This is the Wikipedia information...it describes the fruit as "tasty and nutritious" and can make a sweet drink.
However at the end it says the whole plant is a source of hydrogen cyanide, which ties up with Fourm Member's reply.