If you bought and registered Avid Media Composer 5 between February 8, 2011 and March 8, 2011 you are eligable for a free update to Media Composer 5.5, but you have to download the update before Friday 8th April - which gives you only a couple of days, so act now.  Avid will make no exceptions to this rule.  So download it now or pay for an upgrade!

Visit the Avid protect site: http://www.avid.com/US/support/protect .