DH's aunt had similar issues this year. The first year she was involved with the walk, she didn't feel comfortable registering online, so we went into the team leader's account and signed her up, so people could look her up and donate. Then the next year the CFF sent out post cards to people with their screen names, but freaky long password/numbers. So I don't know if they were still in the system from long long ago and the varied passwords were causing problems.
Anyway, thought they worked out all the bugs in their system, but she and dh's cousin's wife signed up, but didn't show up as part of the team. The CFF rep could see them, but couldn't figure out how they ended up registered 'cuz they were just in limbo. The aunt signed up 3 times before emailing me and I just added her to the team, then I was able to find her screen name and put in a request to send her the password. Then it worked. And it just happened to be the same password that I signed her up with years ago -- my MIL's maiden name.