SAP User ID

Hi,

I have a scenario, for example, user created a user ID 'Sean' (capital letter S) for all DB except one particular DB created as 'sean' (small letter s), because of this, the DB with 'sean' not able to share the license with 'Sean' in the rest of the DB.

The user tried to create 'Sean' at this particular DB, however, it is not allowed, prompted error message 'This entry already exists in the following tables 'Users' (OUSR) (ODBC -2035) [Message 131-183]'. Basically, the system recognise 'sean' as the existing ID.

Beside recreate new user ID for all DB, any other solution for this?

Using SAP 9.1 (SQL).