Sorry to hear about your rejection.
CIC does officially say "Note: Your test results must be valid (less than two years old) when you complete your Express Entry profile, and
when you apply for permanent residence" . Please check http://www.cic.gc.ca/english/immigrate/skilled/language-testing.asp
Hope your next application will be all right
There is a nice summary of reasons for rejection (so that future applicants can avoid similar mistakes) at https://docs.google.com/document/d/1eJ3TNRGHbAOrqvjSrbMgfep6JmIHc0lS48hm89-zIlc/edit?pref=2&pli=1 In addition, there is a lengthy thread at http://www.canadavisa.com/canada-immigration-discussion-board/reasons-for-rejection-t306713.3510.html