Would need some help from sifus here, just got my S3 last week everything seems perfect until last few days. I have some issues with incoming calls and contacts.

When there is an incoming call, the phone rang but the screen is blank. Nothing shown whether to answer or reject and can't see who is calling. Press home button also no response at all.

Other than incoming, outgoing call sometimes have issue too. It shows a dialog box say "unfortunately, com.phone......has stopped" something like that. Sometimes it pops out during conversation, have to press OK before press the End Call button.

Last issue, when I try to add a custom pic to one of my contact, when I load it from Dropbox then it shows "Unfortunately, contacts has stopped".

My phone is a brand new unrooted one, I'm wondering what causing all these issues. I googled ans some suggested factory reset and I did, being well for 2 days then same thing happen again. This is my first android os phone, hope can get some feedback or guidance from you guys to help me out. Million thanks.