My Themes wont stick!!

http://octob3r.org

I have two themes. “Ghost-Ride It” is the default theme and “Nelly” is the other option. I select Nelly and it works for all my subpages but when I go back to “http://octob3r.org” the Ghost Ride theme comes back and the whole site goes back to that theme. Does anyone know what the problem is?

And also, the themes don’t stick on the childpages…