2.1_RC1 won't load on stock leopard setup

when running any of the server, about, console scripts rubygems aborts saying it can't load a gem that is already loaded. this doesn't happen when running freeze:edge

** Starting Rails with development environment...

Exiting

/Library/Ruby/Site/1.8/rubygems.rb:139:in `activate': can't activate activesupport (>= 1.4.1), already activated activesupport-2.0.991] (Gem::Exception)

from /Library/Ruby/Site/1.8/rubygems.rb:155:in `activate'

from /Library/Ruby/Site/1.8/rubygems.rb:154:in `each'

from /Library/Ruby/Site/1.8/rubygems.rb:154:in `activate'

from /Library/Ruby/Site/1.8/rubygems.rb:49:in `gem'

from ./script/../config/../vendor/rails/railties/lib/rails/gem_dependency.rb:32:in `add_load_paths'

from /Users/mike/Work/www/jam/vendor/rails/activesupport/lib/active_support/core_ext/symbol.rb:11:in `__send__'

from /Users/mike/Work/www/jam/vendor/rails/activesupport/lib/active_support/core_ext/symbol.rb:11:in `to_proc'

from ./script/../config/../vendor/rails/railties/lib/initializer.rb:235:in `each'

... 31 levels...

from /Users/mike/Work/www/jam/vendor/rails/railties/lib/commands/server.rb:39

from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:27:in `gem_original_require'

from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:27:in `require'

from ./script/server:3