cached_model broken in Edge Rails

Hello,

I'm getting the following stack trace when I start Edge Rails (5384)
with cached_model 1.3.1. If i switch to Rails 1.1.6, it works fine. Any
help will be appreciated.

$ ./script/server
=> Booting Mongrel (use 'script/server webrick' to force WEBrick)
=> Rails application started on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
** Starting Mongrel listening at 0.0.0.0:3000
** Starting Rails with development environment...
Exiting
./script/../config/../vendor/rails/activesupport/lib/active_support/dependencies.rb:256:in
`load_missing_constant': uninitialized constant Rails::VERSION
(NameError)
        from
./script/../config/../vendor/rails/activesupport/lib/active_support/dependencies.rb:360:in
`const_missing'
        from
/usr/lib/ruby/gems/1.8/gems/cached_model-1.3.1/lib/cached_model.rb:77
        from
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:33:in
`gem_original_require'
        from
/usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:33:in `require'
        from
./script/../config/../vendor/rails/activesupport/lib/active_support/dependencies.rb:400:in
`require'
        from
script/../config/../config/environments/development.rb:24:in
`load_environment'
        from
./script/../config/../vendor/rails/railties/lib/initializer.rb:190:in
`load_environment'
        from
./script/../config/../vendor/rails/activesupport/lib/active_support/core_ext/kernel/reporting.rb:11:in
`silence_warnings'
         ... 24 levels...
        from
./script/../config/../vendor/rails/activesupport/lib/active_support/dependencies.rb:400:in
`require'
        from
./script/../config/../vendor/rails/railties/lib/commands/server.rb:39
        from ./script/server:3:in `require'
        from ./script/server:3