To answer my own question, I have to get webmin uninstalled and then re-install so I can use the default password. Took me a few hours to figure out. I searched the forum, found one place people asked for help due to the webmin lock out and nobody offered any help. I want to share my experience so someone can avoid the problem.
The problem: the webmin login failed for what ever the reason, using the default root password is not working, tried every combination but still not working.
the solution: First un-install webmin:
/etc/webmin/uninstall.sh
then re-install the webmin:
wget
http://prdownloads.sourceforge.net/webm ... noarch.rpm
rpm -U webmin-1.500-1.noarch.rpm
then re-start the webmin:
/etc/webmin/start
Now you can login the webmin using the root as username and your root password as the password.