If you just joined the boards (very recently) and your account was deleted suddenly the past few weeks, that might mean the new spam filter thought you were a spam address. Most likely, you're using an e-mail address that other spammers have used. It looks at the @blah.blah and sees if it's a known spam url. It's the only real way to block the loads of spam addresses that are used.
Try using another e-mail address and reregister.