If I'm not mistaken, your code looked exactly like Steven's code so the mod should have worked the same. I may want to rewrite the mod to be supported on more systems. The only thing I can think of is that the mod requires php5 at the moment but I am pretty sure you have that.
I don't know what's wrong but I'll keep working on it.
I need people with phpbb2-3 installs that are willing to test a new FSpamlist feature that will integrate into your forum software. It comes in the form of an easy mod that will check every e-mail address that new users try and sign up with, and if it is found in the fspamlist database, it is automatically rejected.
I never have any problems with spammers, but I'll ask Steven if we should do this over at my place.