Ok so personal hotspot worked every time with iPhone 4 on iOS4 and MBP on Lion. Now iPhone 4 is upgraded to iOS5 and my MBP has been swapped for a new MBA 13''. The Air connects no problem to home wifi and other hotspots i.e. starbucks but I cannot use the Personal Hotspot on the iPhone via the Air......connection time out EVERY time. However it works between the iPhone and iPad I have. Can anyone shed light on this and a possible solution .....searched for ages but can find any workarounds at all.