SSIS PL/SQL task hangs with message "Multiple-step OLE DB operation generated errors."

I've configured a Microsoft SQL Server 2008 R2 SSIS package with an Execute SQL Task to run a PL/SQL query on an Oracle 10.2 database. The Execute SQL Task (named "SQL Update MY_STATUS flag") is using an OLE DB Connection Manager with a "Native OLE DB\Oracle Provider for OLE DB" Provider. All other task settings are default values. The query is simple: UPDATE MY_TABLE SET MY_STATUS = 1 WHERE MY_STATUS = 0 (Note: This query succeeds when run in SQL Developer with a semicolon terminator. Here the terminator is omitted, because if a semicolon is included, an invalid character error is generated by SSIS.) When I start debugging, the task begins execution and then hangs indefinitely, the package does not complete execution. The debug output window shows this message: > **Warning: 0x0 at SQL Update MY_STATUS flag: Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if > available. No work was done.** (The Task behaves the same with the query configured as Direct Input, or as a Variable.) What does this "Multiple-step" warning mean in this context? What must I do to allow the Execute SQL Task to succeed?