On wednesday I bought CS6 Production Premium, upgrade from CS5, which in turn was an upgrade from CS3. I uninstalled and deactivated CS5 before the new install. While entering my new serial number I was asked for the serial of the qualifying product (CS5). I went to my adobe account and all trace of CS5 is removed as if I had never purchased it. I contacted support and they activated CS6 for me immediately. I then asked for my CS5 serial so that I could install it on another computer but they told me that they cannot give it to me as I have no proof of purchase. I pointed out that they had just activated CS6 as an upgrade from CS5. This to me is beyond bizarre and ridiculous. I do not have proof of purchase from 3 years ago. Adobe knows that I bought it and Adobe removed the details from my account. The online representitive was courteous and helpful and acknowledged that I bought CS5 but could not give me my serial as he was constrained by Adobe's rules.
Atrocious treatment of paying customers.