Why cant you get on your account on Movie Star Planet?

This happens to me all the time. The exact answer...i'm not quite sure but what I did was I went on to play but it said user name or passWord incorrect. I carefully typed it again and the same message again. So i logged of then tried again a couple hours later then i was on! But if it wont log you on a couple hours later just try the next day and if that dosen't work make a new account.