Import Tuning Sets

I'm rebulding a Production database on the weekend, and having problems testing how to import a Tuning set.

Using DBConsole, logged in as SYS.  I import a Tuning Set using an export taken previously.  The tuning sets are for sets for other users (not SYS).

The original owner of the tuning set, has unlimited quota for a tablespace to be used for the staging data.

I get the following errors:

ORA-19374: invalid staging table ORA-06512: at "SYS.DBMS_SYS_ERROR", line 79 ORA-06512: at "SYS.DBMS_SQLTUNE_INTERNAL", line 13060 ORA-06512: at "SYS.DBMS_SQLTUNE", line 6835 ORA-06512: at line 1

What privledges am I missing, and what schema does it need to be applied to (SYS or owner of tuning set)?  There are 4 schemas that has tuning sets to be imported to the new database.