Posted: Sat Nov 12, 2011 10:41 am
Adobe is apparently tightening their upgrade policy as of CS6:
http://prodesigntools.com/last-chance-to-upgrade-adobe-cs2-cs3-cs4-to-cs5.html
http://prodesigntools.com/last-chance-to-upgrade-adobe-cs2-cs3-cs4-to-cs5.html