You're right. "I've ever took" is definitely wrong. "I've ever taken" is correct. But native speakers have to learn their language just like everyone else and they don't always get things right ^^;;;

That is the first time I have ever heard of this particular mistake. "Have took.." sounds very bad to me. Mind you, I heard "I stunk! I stunk!.." watching a DVD (Mildred Pierce) last week. That mistake is more understandable, or maybe it is conjugated differently in different places?