Which versions of knoppix will work with the unionfs klik link?

I'm confused - I know knoppix 3.8 already has unionfs, but I didn't think it was possible to add unionfs to knoppix earlier than 3.8.

I got the error "you are not running 2005-01" when I tried under knoppix 3.4, so I guess adding unionfs to 3.4 is out of the question? (I have a heavily customized remaster of 3.4)