Hi all, 

My iPhone 4S is refusing to do the personal hotspot thing by USB, Wifi or bluetooth. 

Hotspot is turned on, USB is plugged in and iPhone is syncing but hotspot notification is not showing up. I try wifi and get a timeout, I try bluetooth and it says try again. 

I rebooted the phone, same result. I rebooted my machine (Macbook pro), same result.

It used to work.

Why I suspect Chinese involvement ... in March I went to China and swapped out my 2degrees SIM for a Chinese one. The mobile people did the swapping and changing of settings in the shop - so I don't know exactly what they did. With the Chinese SIM card in there, there was no personal hotspot option. 

Any ideas? I'm not a real geek so there may be something obvious I've overlooked.