I had this even though im at home and the phone should be on Wifi, at midnight every night there is data being used that is coming off my allowance.
after speaking to O2 and finding out it is because the iphone reverts back to 3G after the screen locks.
after kicking up a fuss and arguing i should have been told when i bought the contract,
they gave me a extra 500mb of data for that month and reimbursed me the £6
but surely there has to be a fix for this ?
anyone jailbroke their Iphone 4s ??