Undefined method error when loading schema (Win 7)

I'm trying to run an existing project on a new installation of Rails on a Windows 7 machine. When I try to load the schema, I get:

rake aborted! undefined method `full_name' for "\377\376-":String

I can't figure out what is causing the error. My best guess is some kind of gem conflict, but various reinstallations and copious experimentation have failed to get to the bottom of it.

I'm running Rails 2.3.5, Ruby 1.8.7, and MySQL 5.0 and installed Ruby via the one-click installer. Loading the schema on another project was successful, so it must be something related to my specific project code, but I can't see what. If anyone can help, I'd be really grateful.

A trace on schema:load gives:

PS C:\Projects\otwarchive\otwarchive> rake db:schema:load --trace (in C:/Projects/otwarchive/otwarchive) ** Invoke db:schema:load (first_time) ** Invoke environment (first_time) ** Execute environment rake aborted! undefined method `full_name' for "\377\376-":String C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/ vendor_gem_source_index.rb: 50:in `refresh!' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/ vendor_gem_source_index.rb: 45:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/ vendor_gem_source_index.rb: 45:in `refresh!' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/ vendor_gem_source_index.rb: 29:in `initialize' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb: 21:in `ne w' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb: 21:in `ad d_frozen_gem_path' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:298:in `add_gem_lo ad_paths' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:132:in `process' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `send' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `run' C:/Projects/otwarchive/otwarchive/config/environment.rb:40 C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_re quire' C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/ dependenci es.rb:156:in `require' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/ dependenci es.rb:521:in `new_constants_in' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/ dependenci es.rb:156:in `require' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/tasks/misc.rake:4 C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_c hain' C:/Ruby/lib/ruby/1.8/monitor.rb:242:in `synchronize' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_c hain' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:607:in `invoke_prerequisit es' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `invoke_prerequisit es' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:596:in `invoke_with_call_c hain' C:/Ruby/lib/ruby/1.8/monitor.rb:242:in `synchronize' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_c hain' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exceptio n_handling' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exceptio n_handling' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run' C:/Ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31 C:/Ruby/bin/rake:19:in `load' C:/Ruby/bin/rake:19