The root password is not verified during the install even
though it is required to be entered twice. It is
possible to enter 2 different passwords on that screen. The
result is that, at least from my point of view not being a
linux wiz, the installation has to be run again.
What 2 passwords are you entering?? We are not able to recreate here
in the test lab. Typing 1 password in one box and another password in
another box will result in a dialog stating that the passwords must
match. As for being able to change a lost root password, just boot
into single-user mode (type "linux single" at the boot prompt) and
then change it in the shell which results.