I had trouble with this new extension Pun_Antispam not showing image. it was there but it was always clear white. checked cmod. checked I had all the right php ect.....
In the end I searched around and the one on this page over at fluxbb forums worked of the bat for me.. created by gordie.lachance. Using Recaptcha.
http://fluxbb.org/forums/topic/2684/rec … ension-04/
Direct download if you dont want to read the forum. But I think its always nice to pay the author a visit. Ayeeeee ------------------------------> http://tinyurl.com/n7kj7d
It's set only to show up if a new user registers, or a guest wants to post. just what I wanted, All you have to do is go to recapcha Register free and get your 2 free keys. drop the folder in extensions. go back to admin page, extensions. Install it. then add your free keys to the features section. Done!!