The attached testing vdb contains the following namespaces:
LOOKHERE TestPG LOOKAGAIN

If you run the following query via ODBC (JDBC works ):
select nspname from pg_catalog.pg_namespace where nspname = 'LOOKHERE'

It returns zero rows, but if you run the same query with 'LOOKAGAIN' in your criteria you get the one row, It seems that any namespace ending in an E doesn't match via ODBC.