Attached is a diff to fix facebook_form_for for Rails 2.1.  It was 
crashing because of the new form authenticity token.  I slipped in a line 
in helper.rb that adds in the token.  I also stubbed protect_from_forgery? 
out in the rails_integration_test.
Hope that helps,
Richard
-------------- next part --------------
Index: test/rails_integration_test.rb
==================================================================---
test/rails_integration_test.rb	(revision 224)
+++ test/rails_integration_test.rb	(working copy)
@@ -413,7 +413,9 @@
     def fields_for(*args)
       ""
     end
-    
+    def protect_against_forgery?
+      false
+    end    
   end 
 
   # used for capturing the contents of some of the helper tests
@@ -806,4 +808,4 @@
 end
 # rescue LoadError
 #   $stderr.puts "Couldn''t find action controller. 
That''s OK.  We''ll skip it."
-end
\ No newline at end of file
+end
Index: lib/facebooker/rails/helpers.rb
==================================================================---
lib/facebooker/rails/helpers.rb	(revision 224)
+++ lib/facebooker/rails/helpers.rb	(working copy)
@@ -179,6 +179,9 @@
         
         concat(tag("fb:editor",editor_options,true) , proc.binding)
         concat(tag(:input,{:type=>"hidden",:name=>:_method,
:value=>method},false), proc.binding) unless method.blank?
+        if(method !=''get'' &&
protect_against_forgery?)
+          concat(tag(:input,{:type=>"hidden",:name=>
request_forgery_protection_token.to_s,
:value=>form_authenticity_token},false),proc.binding)
+        end
         fields_for( object_name,*(args << options), &proc)
         concat("</fb:editor>",proc.binding)
       end
@@ -581,4 +584,4 @@
     self[newkey] = self.delete(oldkey) if self.has_key?(oldkey)
     self
   end
-end
\ No newline at end of file
+end