Did the kernel give u any error messages when loading?
Could check your boot manager (LILO/GRUB/etc) for any mischievous options.
How is ur console device files working? Things like /dev/tty... /dev/Stty0 /dev/... (was it deleted accidentally due to something, or privileges changed during booting--> Someone's playing pranks?)
Lastly, check on RedHat bugzilla or dev. corner, it could be a bug.