I have implemented EEPC in many customers, and also never seen it before.
But now I see it... the user is able to logon only with caps -lock is on.
In active directory users and computers ensure that the username does not contain caps. If it does, right-click rename the user and change it so that it does not contain caps.
Obviously, that the user has caps, see " domain\T12345".
I mean that this user should logon as "t12345", but not, the user only able to logon as "T12345".
If user tried to logon as "t12345", appear this erros msg "EE050002 Unknown User".
I'm not saying that this is a fix but maybe a workarround. How much work do you want to put into solving a one-off problem which can be resolved by changing the caps on the username?