Spammers getting through

Hi,

I have wordpress multisite setup with buddypress both the latest vers.

It seems like autobots are somehow getting through. My registration form at http://www.stickytrade.com/register/ has a recaptcha in it and this does not seem to stop them unless they have another way of getting through.

When you fill out the form manually it will create a member in the member directory, but the spammer registrations aren't being listed in the member directory (buddypress). Has someone had this problem? Have I missed something when setting up anti-splog? How can I stop these spammers?