I bought Poser 4 at upgrade prices despite the change of ownership... and suspect that most users did. CuriousLabs had no trouble with it and my serial numbers have all worked just fine. In fact, the only graphics company where I've had problems with getting the new serial numbers to "take" is Adobe, and their customer service folks walk my computer through the upgrade installation is since disk-swapping in&out doesn't get out of some weird internal loop. Many companies have sidegrade offers, too... even if they didn't get a penny from your other purchase they want your pennies now. Carolly