I got my /boot 100% full and couldnt update the kernel with its new minor version upgrades. So did some moving around of kernel files to get them updated, but this ended up with a corrupt GRUB. I had to use the live DVD to get my grub corrected. All is well till I found out that my root password got reset (not sure to what). So I had to do the following
$sudo su -
(gave my regular user password)
#passwd
and type the new password.
And that's it.