here is a fix.
boot off the mint CD.
open a terminal, and mount you old / file system
sudo mount /dev/sda1 /mnt
now you set you old / as the current root file system
sudo chroot /mnt
now be careful as you are root.
edit the /etc/passwd file and change your user account name from root to Gabe, the account will have a UID of 1000 NOT 0. save and close.
now exit the chroot terminal
reboot and login as Gabe.
use sudo in the future not the root account.