I've just customized the registration process, so it is now necessary for new users to enter the confirmation code on the screen backwards to prove they're real people. When we had the spam problem with an earlier version of PHPBB, making that change stopped all the spam. Hopefully it will do the same now.
If you're a new user and have trouble getting registered please send me an e-mail at paul@pishtech.com. If you're a #*@&$ bot and having trouble getting registered, that makes my day.

Tight lines,
Paul