This page: http://www.parallels.com/en/products/desktop/, has a link for 'Try now' and 'Upgrade'. The 'Upgrade' link directs to a page where you can buy an upgrade license, nowhere does it say who needs (which versions the person has) to buy the upgrade and who can install it for free, so, a person who already has version 3.0.5584 might be misled to pay for 3.0.5608 when he or she are entitled to it for free.
