I tried changing my admin password today and got locked out of the web GUI.
#1) Id like to consider /Database/var/register/system/ldap/rootpw a security issue as its storing my password in plaintext. But thats what I used to verify my password was indeed set correctly.
#2) my password had an ; in it, I assume this broke the scripts somehow.
I first used kpasswd from the shell to set it to the same password again, and i still couldnt login to the web gui. So I changed it to something else and then it worked fine.