I changed this: try { conn.setTypeMap(this.map); } catch (SQLException e) { into this: try { conn.setTypeMap(this.map); } catch (Exception e) { (Changed all SQLException into normal Exceptions of al the catches) because on the above statement the odbc driver to a access db throws a NotSupportedException so none of the connections where returned to the pool because the source.returnConnection(this); was never reached. Johan compagner