Hi there, I have a problem, my iPhone 4 keeps waking up from standby every 20 seconds as if I´d press the home button whenever I am on roaming or if I remove the sim card. This of course drains battery life like crazy. I tried different settings and restarts but all of this does not help. Furthermore sometimes when I receive calls the slide bar does not react when I receive calls. I´d be happy if someone could help me with this, of tell me whether I should go to apple and have it fixed... thanks!