It sounds to me like you have some grounding issues. Perhaps grounding rods and ther water pipe ground are not bonded together, or no grounding rods at all (older service). The cable blew due to the current flowing through the pipe going to the cable bonding nut and through the cable box (and back down the ground wire probabally).
I would say you have at least 2 problems:
1) High resistance gound (does not allow enough current to flow to trip the breaker.
2) Bonding problems. All grounds are supposed to be bonded together to create an equal potential. Improperly bonded grounds will easily destroy electronic equipment (cable sattilite system, computer networks etc) as they use and link grouns on different points in the electirical system.
It is best for a leader to be both feared and loved. But since this usually cannot be done, it is safer to be feared.