Connecting Oracle with RS

I am having trouble using stored procedures with Oracle 9i in RS. I am getting the following error:

Microsoft Development Environment
An error occurred while executing the query.
ORA-06550: line 1, column 7:
PLS-00221:'SP_GET_STOCKS' is not a procedure or is undefined
ORA-06550: line 1, Column 7:
PL/SQL: statement ignored:


and here's the code in the for the defined package and SP_GET_STOCKS:

CREATE OR REPLACE PACKAGE Types
AS
TYPE ref_cursor IS REF CURSOR;
END;


CREATE OR REPLACE FUNCTION sp_get_stocks(v_price IN NUMBER)
RETURN Types.ref_cursor
AS
stock_cursor types.ref_cursor;
BEGIN
OPEN stock_cursor FOR
SELECT ric,price,updated FROM stock_prices
WHERE price < v_price;

RETURN stock_cursor;
END;

/

Please note that I am just testing yet, although I have completed some repoting using SQL server database:

If you have any idea please let me know.

Thanks a bundle!

Mahfooz