Incorrect result is displayed for ALTER SYSTEM command.
When executed in SQL/Plus:
SQL> alter system set use_stored_outlines = true;
System altered.
When executed in Toad's Editor:
SQL> ALTER SYSTEM SET use_stored_outlines = TRUE
System switch log altered.
WORKAROUND:
None
STATUS:
Issue fixed in version 9.5. The latest version of Toad for Oracle can be downloaded here.