About your application's environment
Ruby version              1.9.3 (x86_64-linux)
RubyGems version          1.8.22
Rack version              1.1.3
Rails version             2.3.14
Active Record version     2.3.14
Active Resource version   2.3.14
Action Mailer version     2.3.14
Active Support version    2.3.14
Database adapter          mysql2
Database schema version   20120301153455

About your Redmine plugins
Environmnet CSS   0.1

Additional Information:

• your database manager version: MySQL 5.1.61
• your Redmine version: 1.4.1

Problem:
When using the REST API to create or modify time_entries, custom_fields are ignored if using XML format. When I use JSON, it succeeds (but only if using some different structure than the one described on the WIKI page http://www.redmine.org/projects/redmine/wiki/Rest_api )

I tried all of the following XML structures:

• The one described on the WIKI page:

  
  changed via XML PUT - 1
  
  
    1131
  
  
  
  

• But also all of the following (the last one is no valid XML but I tried it anyway)

  
  changed via XML PUT - 2
  
  1132
  
  

changed via XML PUT - 3

1133

changed via XML PUT - 4

<4>1134

If I use JSON it succeeds with the following format:

{"time_entry":
  {
    "comments":"changed via JSON PUT - 2",
    "custom_field_values":
      {
        "4":"13:02"
      }
  }
}

• If using the suggested format from the WIKI page, it does not work:

  {"time_entry":
  {
  "comments":"changed via JSON PUT - 1",
  "custom_fields":
    [
      {"value":"13:01","id":4}
    ]
  }
  }
  

Very interesting is, that XML POST/PUT with the documented format (WIKI page) works for issues!
So this succeeds:

  changed via XML PUT
  
    
      0