Are you testing it on your live site (or at least one that you're accessing from the same domain)? I guess for it to work you either have to get to the page through your domain or else localhost.

Oh, then I guess it is your live site.

Yes. My live site.

Update: You were correct, kh99. It was just a short delay updating the API keys.

All working fine now. Thank you. :)

Update: I just added this to to more sites. I can confirm that you can no longer use your old Recaptcha keys. You need to delete the old key and re-register the domain to get new keys.

It is only taking a few minutes for it to recognize the new keys for me today.

Thanks, I'll change the description to say that.

Hmmm... I'm not 100% certain of that now.

I've now added this to 5 forums. On one, I didn't need to change the key - I only added this site a short while ago,

Now I'm wondering if I may have been using a single key for the other forums, that "global key" that Google warns will no longer work.

You might try your old key first and if you get an error delete it and get a new one.

Yeah, I think you're right. I saw somewhere else that the old keys should work, as long as they're not global keys.

After installing, i can test fine without issues, however my reg screen doesn't show the graphics on Chrome or IE.
In addition after disabling it and reverting back to the previous recap it also doesnt show.
http://i.imgur.com/yYw1wCf.png
http://i.imgur.com/PmxqeqC.png

So it does block spam sign ups, the only issue is nobody can sign up now..

vb 4.2.3

--- edit ---
Incompatible with vBSocial 10 Lite
If you could install that and replicate then fix the issue, i'd be super happy.

Just to be clear, are you saying all those issues were cause by incompatibility with vBSocial 10 Lite? I don't know how installing this mod could stop the previous recaptcha from working. Certainly if you uninstall it it shouldn't have any further effect.