After update to 1.9.2.0 I have added the form-key to my registration template.
I can see the form-key value using firebug on the registration page, but when I submit the form, I get a 404 error:
http://dev.pickone.com.br/customer/account/createpost/ ---- 404 Not Found
I am using nginx/1.2.1. Also using onepagecheckout.