Yeah, i got that much, and have been tracking down the Abre los Ojos soundtrack bit by bit since. There's a lot of work on it that I already have (pulled from other cds - Massive Attack, Sneaker Pimps, Amphetamine Discharge, etc), but also some work that may be original compositions? And from the reviews I've read of Vanilla Sky compared to Abre los Ojos, it's a damn near line-for-line interpretation, just with lesser screenplay value. I figure if they're willing to swipe a movie like that, why not contract to swipe a theme from it as well? And given how similar the Chemical Bro's. song is to the one on the commercial, and that it's on the Vanilla Sky soundtrack, possibly the song on the commercial is originally cut off of Abre los Ojos.
...Allow me to step down from the soapbox...
You're right, though... the Chemical Brothers song may very well be an original composition that was only *used* in the movie, not *written* for it, and I could be barking up not only the wrong tree, but in the wrong forest.