[ben509]

I registered an account for some software company that was acquiring some other services, so the left hand wasn't talking to the right.

Sure enough, different parts of the site had different password requirements, and they enforced them on password change. So you could create an account on a sub-site that wasn't accepted on the main site, which was the only site with the password change page, but you couldn't enter the old password to fix it.

I think password reset did work, but I wound up creating another password that worked in one place but not another...