And now i have found a way i want to share with you.(I did not make this video)
Go settings > General settings > Network > Cellular data network
Then you add this :
APN : connect.mobillinkworld.com
MMSC : http://mms/
MMS Proxy : 172.25.20.12:8080
Internet Tehering: connect.mobillinkworld.com
Then i restart the Iphone.
Then after i started Iphone i went to:
settings > General settings > Network > Cellular data network (Again)
and i scroll down to then of Cellular data network
Now you should see Personal hotspot Off
Turn that on and then it should be visible in Settings and now phone might work as it should do.
This also work if you have IOS 5.1
Hope that helped.