[CentOS] The screenSaver is blocked in my centos5.3

> Yeah,  I only use the root account,   how to resolve it?

never EVER log in as root, unless doing emergency system repair, like 
when you are in single user mode because the system won't boot.


create a user account, with a password, use that for all regular 
purposes, and sudo or su to gain root access for specific commands that 
require it.