Not a lot that you can do about it - except returning the CS6 update, and getting the full version. Do remember that Fireworks is no longer developed by Adobe, and is effectively a "dead" application. You may want to invest your money in alternative software.
Alternatively, try to seek out a legit copy of CS5, and update that one. You might be successful on ebay - but there are a lot of illegal versions on sale on ebay, unfortunately.