Hi, i recently joined the iphone world and bought a 2nd hand 3GS 32GB iphone on ebay. Since the phone arrived it seems to shut down randomly but always when using an app, never on the main screen. The phone was already jailbroken when bought and i am wondering whether it could be down to this? I am totally new to iphones, and not technically adept but when querying about it being Jailbroken the seller explained what it was and it sounded OK to me. The only other possibility is that i am on Tesco pay monthly contract, not an iphone deal either, just a standard month to month deal, but i assume their iphone deals only difference is the usage you have available - is that right or could that be the issue? Any help, advice would be greatly appreciated.