windows のホームディレクトリ（C:\\Users/xxx）配下では rubocop が正常に動かない？

ruby windows

以下のようなエラーが出て動かない。

different prefix: "c:/" and "C:\\Users/xxx"
C:/Ruby193/lib/ruby/1.9.1/pathname.rb:465:in `relative_path_from'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/path_util.rb:10:in `relative_path'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/config.rb:91:in `path_relative_to_config'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/cop.rb:164:in `file_name_matches_any?'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/cop.rb:152:in `exclude_file?'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/cop.rb:156:in `relevant_file?'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/commissioner.rb:86:in `block in invoke_cops_callback'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/commissioner.rb:80:in `each'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/commissioner.rb:80:in `invoke_cops_callback'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/commissioner.rb:55:in `investigate'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cop/team.rb:36:in `inspect_file'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:101:in `inspect_file'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:69:in `block in process_file'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:67:in `loop'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:67:in `process_file'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:23:in `block in process_files'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:21:in `each'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/file_inspector.rb:21:in `process_files'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/lib/rubocop/cli.rb:31:in `run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/bin/rubocop:14:in `block in <top (required)>'
C:/Ruby193/lib/ruby/1.9.1/benchmark.rb:295:in `realtime'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rubocop-0.20.0/bin/rubocop:13:in `<top (required)>'
C:/Ruby193/bin/rubocop:23:in `load'
C:/Ruby193/bin/rubocop:23:in `<main>'

win版rubyにはいろいろ問題あるようで…
特にVista以降はホームディレクトリがなんだか特殊なディレクトリになっているようだし、ホームディレクトリにはソースを置かない方が良さそう…