oracle RPC bug   (link)

http://www.jusungyang.com/ORACLEfolder/plsql/Interesting/PackageState.txt

SQL> -- RPC problem with ORA-4068

SQL> -- When a remote procedure is recreated after it has been executed from another db,

SQL> --   the first subsequent call to the procedure from this db will fail.

SQL> -- I consider this to be a bug.

SQL> 

SQL> -- Error can be avoided by flushing the shared_pool of the calling db,

SQL> --   or by slightly changing the text of calling the procedure

SQL> --      this will create a new entry in the shared pool

SQL> --   or simply by calling the procedure a 2nd time.