Apache proxy lighttpd

Hi, I’m trying to setup up a rails deploy environment. I get an error
when start lighty in production.log

undefined method downcase' for nil:NilClass /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_controller/request.rb:17:inmethod’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_controller/base.rb:902:in
log_processing' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_controller/base.rb:380:inprocess_without_filters’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_controller/filters.rb:377:in
process_without_session_management_support' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.3/lib/action_controller/session_management.rb:117:inprocess’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/dispatcher.rb:38:in
dispatch' /usr/local/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/fcgi_handler.rb:150:inprocess_request’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/fcgi_handler.rb:54:in
process!' /usr/local/lib/ruby/site_ruby/1.8/fcgi.rb:606:ineach_cgi’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/fcgi_handler.rb:53:in
process!' /usr/local/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/fcgi_handler.rb:23:inprocess!’
/var/www/html/myxxt/public/dispatch.fcgi:24

ruby -d dispatch.scgi:
Exception `NameError’ at ./…/config/boot.rb:14 - uninitialized constant
Rails

Any one can help me?
thanks