Did you get the phone brand new from a carrier store, or used/refurbished from some reseller? What's the exact model number listed on the sticker on the box? Does it match the model number in the Settings>About Phone menu? I'm wondering if a previous owner might have flashed a different variant's firmware onto the phone, which could lead to glitches like this. A factory reset wouldn't help, since it would still be using the same firmware.