Didn't I read somewhere about someone running one of the purchased apps on an older OS release? Hopefully simply running in 10.5 or older 10.6 version isn't a way around the licensing/protection scheme.

I did read a mention somewhere a while back that someone had already broken the protection scheme though. Hope that's not true and it's at least as sophisticated as what I'm using now. By the very nature of having every app using the same scheme however, it's a much easier target for being eventually figured out.