u seem to hav the same problem as i had. u need to login as a single. that means that u hav to login by one user.
u will hav to check out the intial bootup thing, on the choice menu press 'e', u will get some choices, step down to the choice that starts with 'kernel' select that choice and press 'e' again. u will go to command with this command to edit, go to end of the line and print '1' without the quotes obviously, and then press enter (return). u will be prompted for the command then, type 'passwd', and press enter. now the prompt for new password will be seen. type new password retype it, and ur thru as root sweetheart.