I have a small problem (?) with my 1 week old iPhone 5. I have noticed yesterday that when phone was plugged to the charger it vibrated once with no reason. Vibration was the same kind like when you switch the phone to the silent mode. The phone was on a table and when it vibrated, it did not turn screen on or show other notifications of any received or updated data. I have also checked all possible apps for any updates but no new messages in Whatsapp, facebook or any other app. I have seen some topics where problem was that email was on automatic update and phone vibrated upon arrival of new mail but my automatic update of email has been turned off since the day 1 and in my case this is not the problem. Do you have any advice what else this might be?