Hi! I've read in many different places that on the contrary, coconut oil is the BEST for cooking because unlike other oils, it precisely does NOT break its chains when it's heated. So it remains stable and doesn't burn or turn black either when you cook with it.
But it is true that it must be the unrefined kind, don't get that refined, bleached, tasteless kind that I find everywhere in Asian grocery stores. Those are REALLY bad and often they are even already rancid by the time you buy them. They turn black immediately and stink when you cook with them, horrible horrible.
No, the experience is totally the opposite if you cook with unrefined, cold-pressed coconut oil. Hope that helps.