I purchased CS5.5 Design Standard in late April, and took advantage of the free upgrade to CS6 when it was released. I am finally getting a chance to install CS6 right now, but the program is now telling me that my CS5.5 serial number is INVALID!! What gives???? I didn't shell out this much money for this kind of treatment.
I am having the same problem. I have tried the installer a few times, but haven't had any luck. Also haven't been able to contact anyone to try and solve this, and I can't find any solutions anywhere.
I went the this link, and clicked the chat now button. Customer service was able to help me in just a few minutes. They asked me to shift+cntrl left click in the dialog box that asks for your cs5 serial, and a new window pops up for a support number. Gave them the number then they gave me a code, and was able to install cs6.it wass very easy to do.