Using blocks in erb / abingo

Hi guys,

I'm using abingo to a/b test on my website. I have a buttong that I would like to test with different words. Currently I have the test set up like so: <% ab_test("signup_test", ["START YOUR MEMBERSHIP","SIGN UP", "CLICK HERE"]) do |button_text| %>   <%= button_to button_text, :new_user_registration, {:method=>:get, 'data-theme'=>'mp', :onclick=>"_gaq.push(['_trackEvent', 'Users', 'Sign Up']);"} %> <% end %>

This seems consistent with Ryan Bates screencast on abingo

For some reason, I'm getting the weirdest error:

undefined method `block_called_from_erb?' for #<#<Class:0x105432050>: 0x10542fff8>

I have tried to google this, but to no avail. Any hints, ideas as to what this error may mean? Why does it not like my block?

Thanks in advance. Regards, Robert