FAILSAFE error when attempting custom POST - How do I fault find for this?

Hi,

I'm creating the file upload code in a C# web form to upload to my Rails app. When I start the upload I get the following error on my Rails server? Any ideas how I can fault find here?

It could be the case the HTTP post I'm creating has a problem (it' multipart, with a file upload + some form parameters) however it's hard to tell from Rails what it is causing it?

/!\ FAILSAFE /!\ Tue Jan 12 08:20:06 +1000 2010   Status: 500 Internal Server Error   bad content body     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/utils.rb: 351:in `parse_multipart'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/utils.rb: 323:in `loop'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/utils.rb: 323:in `parse_multipart'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/request.rb: 133:in `POST'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/ methodoverride.rb:15:in `call'     /opt/local/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/ action_controller/params_parser.rb:15:in `call'     /opt/local/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/ action_controller/session/cookie_store.rb:93:in `call'     /opt/local/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/ action_controller/reloader.rb:29:in `call'     /opt/local/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/ action_controller/failsafe.rb:26:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb: 11:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb: 11:in `synchronize'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb: 11:in `call'     /opt/local/lib/ruby/gems/1.8/gems/actionpack-2.3.3/lib/ action_controller/dispatcher.rb:106:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/rails/rack/ static.rb:31:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb: 46:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb: 40:in `each'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb: 40:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/rails/rack/ log_tailer.rb:17:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/ content_length.rb:13:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/chunked.rb: 15:in `call'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/ mongrel.rb:64:in `process'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 159:in `process_client'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 158:in `each'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 158:in `process_client'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 285:in `run'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 285:in `initialize'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 285:in `new'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 285:in `run'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 268:in `initialize'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 268:in `new'     /opt/local/lib/ruby/gems/1.8/gems/mongrel-1.1.4/lib/mongrel.rb: 268:in `run'     /opt/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/ mongrel.rb:34:in `run'     /opt/local/lib/ruby/gems/1.8/gems/rails-2.3.3/lib/commands/ server.rb:111     /opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'     /opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'     ./script/server:3 ^CExiting

thanks