... "Unobtanium" was a JOKE, people. An intentional JOKE (albeit based on an actual term used by engineers and space-folk at JPL). Stop with the snarky e-mails. I don't know why I just got a pop of them, but if you don't get that tongue was firmly in cheek for a chunk of the movie, then you need to maybe stop thinking you're on the topside of the argument on this.
And yes, it should have been magnetic pole shift. That's what it was originally. I can only take small solace in the pleasure that everyone who "noted" that movie into the ground is now not just unemployed, but spectacularly so. Gahhh.
On the other hand, it developed a nice little fan base once it was on DVD, so I'll take the win.