hey ive had the HTC desire z for about 6 months now, has been working fine but recently my little sister guessed my security pattern wrong too many times resulting in my phone getting locked and needing to be formatted. after the format ive realised the mobile network settings had also been erased so i decided to put them back in. at first they were working fine but now the inernet does not turn on, when i turn it on it goes off by itself seconds later. wifi is working fine tho. any ideas??