I have a 2012 MBA on 10.8.3 that refuses to play well with Personal Hotspot on my iPad mini and my iPhone 3GS. My old white MacBook (running 10.6) and first generation iPad work perfectly well but when I connect my MacBook Air via Personal Hotspot the Internet dies after opening a site or two. The devices seem to have no problem in connecting with each other but the Internet connection is extremely unreliable and very sporadic. I've tried connecting over both Bluetooth and Wi-Fi but the problem persists. Any ideas on what I can do to solve this issue? Also, on an unrelated note, the 3G connection on the iPad mini seems to be sluggish at times when compared to my older iPhone 3GS even though they are both tied to the same service provider (Vodafone India). Could this be a user account/sim related issue or is something else at play?