init 1 is Single User mode, you supposed to be able to login as root automatically in single user mode (obviously)
init 0 = shutdown/poweroff/halt
init 6 = reboot
What happens when you enter "linux 1" at the grub prompt?
What runlevel are you in when you attempt "init 1"?
linux 1? you just have to add a "1" at the end, and you will be automatically logged in as root user (single user mode) and receive a bash shell. Useful when you forgot your root password.