It's an issue the occurs when jb updating
I used the entitlement check hack and when installing JB over my first phone it wouldn't actually turn the Tether on it would just sit their saying activating. on my second Razr I made sure to change the check value back to 0 and it updated with no issue and could activate the hot spot hack. Foxfi doesn't work on Razr's running JB but I have been told Wifi Tether the app workes. Foxfi works via Bluetooth though from what I am told but the entitlement check works fine...