I stumbled upon this page while researching a similar error (the JSF @ManagedBean annotation did work though). The fix to my problem was maddeningly easy: I had to add an (empty in this case) beans.xml to the WEB-INF folder. Only then does CDI kick in apparently.
Hope it helps either you or the next stumbling guy!
Yes, stick beans.xml in every META-INF and WEB-INF dir you can find ;-)