I was just testing out the checkout process for a client. On the 'Create Buyer' page, I added in the password that I wanted.
Well, when I go to try and log in, the password I entered was not working. So I requested my password via the 'forgotten password' link and the password that it emailed back to me was NOT the password I entered in.
The password I entered in had special characters [[[Redacted]]]
maybe this is not what is happening at all - but this is what I think was happening.