[Q] Vibrate as crashing app at pin screen topic

I got a strange problem. Maybe no big deal but it is annoying :) When I restart or start my phone I got double vibrate as an app has crashed but no crash popup or anything. If I leave the phone and not enter the sim pin at once the vibrate comes after some seconds. If I am quick and enters the pin directly I can se my launcher and then the vibrate comes. Have made a hard reset and even reflashed it - running the lastest UK software. Any one got some idea what it can be? This is with a clean phone and no apps installed.