The forum is still suffering sporadic spam attacks from some nice guys in Russia.
I'm trying to find the best compromise between security policies and decent user experience. I installed a new captcha system, trying to block the bots registrantions.
I'm sorry for any inconvenience.
If by any chance your activation has been declined in the previous days, please register again, wait for the approval. Posting a message on the welcome forum is always a good practice.