My Oracle Client is:
Oracle Database 11g Enterprise Edition Release 11.1.0.7.0
I ran the script against a local 11g database.
I also tried it against an Oracle9i Enterprise Edition Release 9.2.0.1.0 database which resulted in PL/SQL Developer crashing. But in previous versions of the Oracle Database and/or PL/SQL Developer I think it was needed to use getclobval or getstringval to avoid an internal Oracle error.
I am using PL/SQL Developer version 7.1.5.1398.
Bo