I dont understand why it's just like dat...

I view picture from iphoto in the Events. All portrait pictures is rotated to view but not actually rotate. When I uploaded those portraits pictures into hi5 account, those pictures are just not rotated yet. I checked on apple website about iphoto tutorial, it's not the way my iphoto display pictures. I do not understand why. Please help. Or you have any third party apps for rotating pictures, I will be appreciated.