If they are human,
StopHumanSpam (included in
TAC AntiSpam :
http://xenforo.com/community/resources/tac-tenants-anti-spam-collection-anti-spam-free-version.1474/)
They are most likely to be bots (the spam you have recently seen.. were they from new users or users that
existed before the time you installed FoolBotHoneyPot)
FoolBotHoneyPot is also included in TAC (It stops 100% of spam bots from registering, but if they were already registered, then they'll still spam)
FoolBotHoneyPot stops 100% bot spam on the registration page (it also tells you a lot about the bots/humans ... including header information, proxy information, js information, cookies, how many hidden fields they get picked up by, if they get detected by AnyApi
Also included in TAC and to be used with FBHP is
AnyApi, this is set up by default with StopForumSpam, Project Honey Pot Http:BL, FSpamlist, Spam Busted,Bot Scout ... up to 10 APIs defined by you if you should need that, to be honest, once FBHP is installed, additional API's are pointless, I just use FBHP + StopFormSpam for humans)
Also included in TAC is
StopCountrySpam - to stop Spam from particular countries
Also included in TAC is also
CustomImgCaptcha - these are customised images defined by you. XRumer can not solve custom Images that it can not train against (it can solve mass used CAPTCHA such as ReCaptcha , or Games/Javascript used in other popular CAPTCHA, since it can train against the set, but it can not train against custom images that are different for every forum!). Also, for ever image you upload, there are more than 300K different versions, making a binary comparison harder
No bots can currently get through FoolBotHoneyPot (It would requier a significant redesign for XRumer). If you still belive they have, please can you PM me your logs with FBHP installed, the username of the spammer and also find it in the FBHP logs (it will be there if the bot/human registered after the date that FBHP was installed)