Software does not become unstable due to any type of O.C. The only exception is very old software like the original Doom game as it was cpu dependent for play speed. When run on modern cpu's it runs so fast as to be unplayable. This is not exactly the same as saying it is unstable but as close as it might get. As to your friend, well ask him why he clings to incorrect information? If he has some documentation to support his view please post some links.
well he doesnt have any documentation that is the stupid part. e jsut found someone saying it somewher some time ago on the internet .he has no idea where