Default Storage Problems

hello guys today i found something weird about my phone
actually i was running on a CM11 rom but i didnt like it so i flashed this stock rom (Build number:JSS15J.O9300XXUGNA5 ,Baseband Version:I9300XXUGNA8) via odin. now when i go to check my storage i find this
Quote:


as the screenshots show, my storage information are not accurate at all.
so can someone explain me this please?
thanks.