the best advice is not to count only on one article directory. yes ezine is the best but still they can change their policy one day, so i advice you to spread your articles on other directories as well.
Yeah I have the same problem too.. I have 6 articles approved on ezine, and 4 articles are declined I follow their rules and there's no mistakes on spelling, grammar or structure.. Premium membership is very expensive.. it's $97 per month Gosh, they get free unique articles and earn from our content, but they make things difficult..