I'm not sure that this would be considered a bug, since many people will object that it's better to use lower case names with PostgreSQL, anyway I really need to preserve exact case in tables and field names.
The problem is that in a few places of the PostgisDataStore code (I didn't managed to identify all of them) lower case is assumed, that is no double-quoting is added around names.
This is true particularly in the createSchema() code, but there're other parts affected.
I have a fixed version of PostgisDataStore (albeit it's not general enough to be used as is) that fixed almost all of the above. Where and how can I submit it???