This is very odd... I recently checked my phone and all my messages had disappeared and had been replaced wth about 10 messages which appeared to be from somebody elses phone. This person had been texting people in the usa and uk and guessing from the messages was in the usa. I am in europe. Also all of my numbers disappeared and i had this persons appointments in the calender on my phone. The only changes i had recently made to my phone were to install an app killer and a media player. I removed the media player and my numbers soon returned but i lost all my messages and the new messages and calender stayed the same. Any ideas whats going on? I installed avast and its found nothing.