Understandable, but really I think you've been very lucky not having any major failures. When you think how intricate a CPU is (let alone one with four cores) I think its amazing that there aren't many more failures. Its very very rare for a chip to cause problems, and when they do its often because the user has been overclocking it beyond what it was intended to reach. Lets face it, few of us have any real in depth knowledge of our systems, and yet we push them beyond there limits routinely....
Good luck with the replacement, now if THAT one is dodgy then yeah, go ballistic, LOL