Redmine

I'm trying to update issues in a working Redmine 1.3.0 system using PHP/cURL and/or PHP/cURL/ActiveResource.

But every request I do results in internal server error 500 and a crash detailed in Apache error log

I have now gone so far that I've tried to run cURL separately (exe-file in Windows...) - same result, a crash.
I followed this: http://www.redmine.org/projects/redmine/wiki/Rest_api_with_curl

My curl command (credentials removed, issue exists):

curl -k -v -H "Content-Type: application/json" -X PUT --data "@1234.json" -u ****:**** https://****/issues/1234.json

The 1234.json file:

{
    "issue": {
        "subject": "Test",
        "notes": "Test using Win32" 
    }
}

Error log:

NoMethodError (undefined method `[]' for nil:NilClass):
  /usr/lib/ruby/1.8/phusion_passenger/rack/request_handler.rb:95:in `process_request'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_request_handler.rb:207:in `main_loop'
  /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:374:in `start_request_handler'
  /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:332:in `handle_spawn_application'
  /usr/lib/ruby/1.8/phusion_passenger/utils.rb:184:in `safe_fork'
  /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:330:in `handle_spawn_application'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `__send__'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `main_loop'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:163:in `start'
  /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:209:in `start'
  /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:262:in `spawn_rails_application'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:126:in `lookup_or_add'
  /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:256:in `spawn_rails_application'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:80:in `synchronize'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
  /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:255:in `spawn_rails_application'
  /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:154:in `spawn_application'
  /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:287:in `handle_spawn_application'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `__send__'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `main_loop'
  /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
  /usr/lib/phusion_passenger/passenger-spawn-server:61

What is wrong?