Problem after updating Galaxy S3 to Android 4.1.1
Most probably it looks like a OS issue, might be firmware related, might be kernel related. Have you tried a factory reset? Or sometimes even a reboot might clear things up. If 4.1 is not working well for you, you can always downgrade by flashing an older firmware via ODIN. Get you firmwares from http://samfirmware.com. You will need to register in order to download files from there.