I've made a little script that ran trough the memberlist and checked for spam bots with a spam database (stopforumspam.com).
It removed in total 454 (of the total 884 members registered) accounts that were registered here, had 0 posts (Thats what a mod took care of) and were in the spam database.
This should also solve the issue with the birthday bot giving happy birthday's to bots
The forum should run a bit faster too.