ActiveRecord collection to_json fails

Really strange problem today, it appears that 1.1.3 has an issue. Upgrading to 1.1.4 fixed the problem.

>> Artist.all.to_json
ArgumentError: wrong number of arguments (2 for 1)
	from /usr/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/pure/generator.rb:300:in `to_json'
	from /usr/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/pure/generator.rb:300:in `json_transform'
	from /usr/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/pure/generator.rb:299:in `map'
	from /usr/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/pure/generator.rb:299:in `json_transform'
	from /usr/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/pure/generator.rb:272:in `to_json'
	from (irb):7