Quite a while ago now Daihard and I made a change to the board so that all requests for new users had to be approved by one of us. This is largely down to the fact that we get incessant bot raids (likely from adult content sites), looking to spam the forum with needless and bothersome nonsense.
It usually takes us less than 24 hours to process the genuine requests and deny the bots, but sadly we do get bots charging in with a very large number of new user requests and it can take a while for us to fight our way through the mess (and it's not a simple process).
If you've tried to make a genuine account and you can't log in because it's been caught in the latest bot cleanup, then please accept my apologies.