While the link is to the Patent Application, if you check the PAIR system, it was indeed GRANTED (notice of allowance was sent) on March 12, 2012. Why is the p

While the link is to the Patent Application, if you check the PAIR system, it was indeed GRANTED (notice of allowance was sent) on March 12, 2012. Why is the patent office granting these sorts of patents when there's clearly prior art here? Or at least it fails the "obviousness" test. What's going on?