Hi all - I've got an iPhone 3GS (model MC133B, modem firmware 05.15.04). I jailbroke it when I was on 4.1 and GPS stopped working (I've seen this as an issue). I put the official 4.1 back on but still GPS wasn't working. I've since flashed 4.2 on it and even set it up as a new phone but still to no avail. Can anyone help please? Thanks.