ActiveSupport 2.3.5 and json 1.2.0 gem

Hey,

I've tried every trick I can find, yet I'm still unable to get the
json gem and ActiveSupport to play nice.

No matter in which order I load json and active support, I still end
up with: NoMethodError: undefined method `[]' for
#<JSON::Ext::Generator::State:0x104b7fac0>

I'm trying to use the JSON object directly, *not* as a ActiveSupport backend:

JSON(:one => 1)

NoMethodError: undefined method `[]' for
#<JSON::Ext::Generator::State:0x104b7fac0>
  from /Users/ian/Projects/foo/vendor/rails/activesupport/lib/active_support/json/encoders/hash.rb:45:in
`as_json'
  from /Users/ian/Projects/goo/vendor/rails/activesupport/lib/active_support/json/encoders/hash.rb:34:in
`to_json'
  from /opt/local/lib/ruby/gems/1.8/gems/json-1.2.0/lib/json/common.rb:183:in
`generate'
  from /opt/local/lib/ruby/gems/1.8/gems/json-1.2.0/lib/json/common.rb:358:in
`JSON'
  from (irb):1

{:one => 1}.to_json

=> "{\"one\":1}"

Any ideas?

Thanks