The free Bryce3D on the cover of 3DWorld magazine was released specifically to encourage upgrading to Bryce4, and there was a special offer page in the magazine for that purpose. The 'problem' is that the upgrade offer was made by, and only available from, 'Upgrades Unlimited'; a UK company (a division of Computers Unlimited) - and so probably limited to UK readers. This promotion (and the similar one with a free Poser3 release) was the work of 'Computers Unlimited', which was the UK distributor for the MetaCreations products. As far as I'm aware, the upgrade packages they offered were 'old' MetaCreations stock, not stuff from Corel or Curious Labs. I haven't heard of MetaCreations Bryce and Poser upgrade disks checking for previous versions. I believe that the MetaCreations upgrade versions were exactly the same as full versions except they came without a box. They were functionally 'full' versions and came with their own serial number. They did not make a search of the hard drive for a previous version, or ask for a CDROM or old serial number. The onus was on the retailer to establish that you were entitled to an upgrade version. This is certainly how it was for me in the UK with my upgrades to Bryce and Poser. I heard from friends that it was the same system used in the USA as well. There was no time limit whatsoever on the retail upgrade version of MetaCreations Bryce4, and it was available up to and beyond the end of MetaCreations (and is probably still available from some sources now). The only time limit was for a free upgrade (direct from MetaCreations) for people who purchased Bryce3D within a couple of months either side of the Bryce4 release date. I don't know about the Corel operation.