If a user's e-mail address/Standard ID in their Person record is set up as Joe.Bloggs@hansaworld.com, they are able to register this as their Standard ID. However, when they try to log in with this address, it says "Incorrect username or password". If you change the login to all lowercase i.e. joe.bloggs@hansaworld.com, it allows you to log in.
Why would the Standard ID be case-sensitive, when e-mail addresses are not?