I have a rails backend and am testing the following jquery code against it:

  var content = $("#notification_content").val();
  var data = new Object();
  data.content = content;
  $.ajax({ url: "/notifications/detect_type.json", type:"POST", data: data, success: function(result  ){updateTypeDropDown(result)}});

This code works fine in Chrome and IE. However in Firefox (using Firebug), I see this: http://localhost:3000/notifications/detect_type.json 406 Not Acceptable

here is a chrome request in the log:

Processing NotificationsController#detect_type (for 127.0.0.1 at 2010-12-21 17:05:59) [POST] Parameters: {"action"=>"detect_type", "content"=>"226 south emerson denver co 80209", "controller"=>"notifications"} User Columns (2.0ms) SHOW FIELDS FROM users User Load (37.4ms) SELECT * FROM users WHERE (users.id = '1') LIMIT 1 Completed in 58ms (View: 1, DB: 40) | 406 Not Acceptable [http://localhost/notifications/detect_type.json]

here is a firefox request in the log:

Processing NotificationsController#detect_type (for 127.0.0.1 at 2010-12-21 17:06:41) [POST] Parameters: {"action"=>"detect_type", "content"=>"226 south emerson 80209", "controller"=>"notifications"}
User Columns (2.1ms) SHOW FIELDS FROM users
User Load (30.4ms)
SELECT * FROM users WHERE (users.id = '1') LIMIT 1 Completed in 100ms (View: 1, DB: 33) |
200 OK [http://localhost/notifications/detect_type.json]

I'm stumped. Ideas?