It sucks.

I'm an admin at marvelmods.com and we have the same problem. I'm sure you've got it covered, but here's what I did to regulate it:

1-Registrations require approval. So now there's a queue that I can sort through to reject the spam accounts right away.
2-If I'm unsure on an account name/email, I check it at stopforumspam.com

From what I understand some forum creators have released updates for their products, but the update for ours won't fix the issue, so this is a great temporary solution in the meantime.

Why not also implement a short questionnaire only a human could fill out?

We did. It didn't work. The spambots are being registered by humans.

Sucks plums that. I've got no idea how to get round that. Besides HARD MATHS TESTS so that the army of captcha crackers can't do it.

But then we'd only get superhumans as new users... <.<

Superhuman spammers would be awesome.

We have spam problems?

I think we're taking the wrong approach to these "spammers"; we should recognize the ingenuity and majesty of the common Chinese worker and concede it's inevitable they will crack whatever security we can come up with; therefore we should provide these fellows with a subforum to present their wares in a logical format. This subforum would also serve as a place for the common Chinese businessman to network and socialize with his fellow Chinese businessmen. Maybe we can even create a Mahjong java applet built into the forum for the times these fine businesspeople have down time and would like to play?

This is my advice. I have found these so-called "spammers" are decent people who should be treated as such; one of them even accepted my friend invitation. The only explanation I can think of for your natural aversion to honest businesspeople trying to make a living is that you possess paranoia of a "Yellow Peril".

Shame we cant block spammer countries...

Starting with Finland.

just do a java applet that takes them to irc, have them approved by an admin there

what why

If we're looking just for admin/moderator approval, vB already has that ... I imagine the staff would get tired of having to constantly approve new members though

Because new people register so often.

My vb was getting hit with bots. We added about 8 more fields that are required on registration and haven't had an issue since, well that and we relocated the board on the server.

We have multiple new registrations every day, actually.

.