I bought a Parallels 4 upgrade on the day it was released. I got an activation key, but it asked me for a previous activation key for the version I was upgrading to to complete the process. I had upgraded to v. 3 last year, so I entered that number. That didn't work. So I got a temporary number until I could sort things out. Today I'm trying to sort this out. Late in the day after I purchased the upgrade, I got a second email from Parallels stating that the earlier number was duplicated, so I was given a new activation number. So here's where I stand: when I enter my new activation number, it takes it, but asks me for my earlier activation number from the version I'm upgrading from. I enter my original v. 3 activation number, but it doesn't take that either. I can enter the activation number I got off the disc sleeve from my original purchase in 2006 and it doesn't like it either. How am I supposed to upgrade this product?