Due to the huge amount of bandwidth being used for the downloads, and small amount of contributions (maybe $30 over the last 3-4 months), ftp access has been restricted to those who have contributed to the site (whether money, articles, or just generally helping out). If enough people help out with the costs of maintaining the downloads, we'll open it back up to the public. Until then, you have to be a contributor yourself to get access.
Edit: FTP has been re-opened with a max of 3 users. If you want guaranteed access, you are encouraged to contribute to the site. You don't have to send money to contribute, we'd actually prefer you to contribute content for the site (how-to's, articles, etc.).