Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B179 Safari/7534.48.3)
I think its an issue related specifically to the carrier profiles in ios 5.1 for ipad.
I know that 3, T-Mobile, Virgin Media and 02 sims that have been tested to work with the personal hotspot feature successfully on the iphone 4/4S dont dont work in the new iPad with the hotspot function ans menu doesnt even show. Apple need to fix this.