Backing up freeradius

Hi; I have freeradius configured on Fedora Core 6, I tried to configure a backup script where I can copy /etc/raddb folder to another server with the same version and the same operating system. When it's done, the command service radiusd start did not work, But radiusd -x & worked and the server is well functioning. What could be the problem? Thanks Elie Hani