I first remove a repeating event from the calender, but it removed not only that event (whole series), but also ALL my calender events !! after a pause deciding what to do next the screen saver started, I press the finger switch to bring it back and it said 'initializing finger sensor', it just stood there I can do nothing, so I decided to force it power down by removing the battery, coz I remember all smartphones I used (Nokia as well) will not save back changes immediately, so I still have a chance to recover my lost calender, yes the calender came back upon restart, but only that deleted event with a red '+1' next to it, I've never see that before, I decided to redo the calender anyway... I created a repeated event and then an one time event, but I forgot to change the date, so I change the date of that one time event, but it won't save back change, it just lock to the wrong date, I've to remove it and create again !! I don't know if the finger sensor has anything to do with the calender problem, but both of them definitely need a re-work !! for instance, all the feature phones can delete pass calender events base on a date, but that 'feature' doesn't exist on the 'advanced' Android phone, I don't know this is the Android OS or the phone's design limitation, hope to see 'improvement' in next update !