Let me get this straight: most of those European countries perceive Europe to be a separate continent because of a mountain range from that of Asia... but the tiny little isthmus between North and South America is not enough to declare them separate? (no offense intended to Panama)

I don't really care to be honest; I learned that there were 7... but if there were going to be only 6, it should be Asia and Europe that are combined, but my guess is there is more than geology dictating that decision. That Wikipedia link also mentions the 5 continent model, which also would seem to be more correct than a Europe being a separate continent.