My phone still has it's original Samsung battery but once in a while it will stop taking a charge. For no apparent reason, it gives the message 'unauthorized battery' & won't take a charge. I've tried different chargers, pulling the battery with the phone on and with it off. It always seems to do this when I need the phone the most - probably just a coincidence, but still... It eventually will take a charge without any specific action on my part. Anyone else having this problem?