If you say that one more time, I am going to get angry. A proper stable overclock with proper cooling can last for the life of your computer. Unless you are seriously overvolting past manufacturer's specs, there is no reason why an OC would just flake out unless there is hardware failure somewhere....as in this case a bad ram chip.
TO THE OP:
It sounds like you have a bad stick of ram to me. If the ram passes memtest86, then you need to download HCI memtest and open 4 instances. Run 3 of them at 1024 and the last at "all unused ram". See if they all reach 100% coverage with no errors, if not, bad stick.