"Non HW: Max 4 uses it. I have yet to find a crack but that's not to say that it hasn't or won't be done. It's been out since around January." It has been done. Period. Maci is correct and you are wrong. The crack breaking Max 4 and making it a fully authorised commercial version has been out for some time now. We are in what? April. Assume the crack was only done last week (unlikely). Then that particular vaunted software protection (by a very large software firm for their $3000+ package) lasted 3 months. Poser is so popular (kudos to your product) that I doubt less energy will be expended by the crackers on cracking the ProPack bugfix than in cracking Max 4. I would speculate that the crack for your planned protection will simply fool the program into never asking for online authorisation, making duplicate serial numbers moot. By all means implement your protection, but at least be realistic about what it is aimed at doing; preventing picayune copying by people who never look at warez sites. It won't succeed in "curbing warez"