Don't think your IP banning is working, they are all coming in currently from 89.74.102.102 this is banned along with 89.74.*.* but it has been for a few days
Dan , just a suggestion give the keys to the board to a few more members who log on regularly with a specific remit to delete spam posts that way there are more than just Alans eyes on the ball . I remember years ago on another forum about this size there were 10 mods mostly part time (who were members of the forum) but between them had eyes on the board almost 24 / 7 and most spam posts lasted on average 30 mins or what about a sandbox to post new posts to then when the post has been checked by a mod it is then posted on to the forum this option for new members only until their trustworthyness has been established ..spammers they never quit unless you make it hard and unproductive for them ..
ip banning does not work with spammers using anons and proxies all day long its not an effective tool unless things are different to what I remember ???.