Mongo 2.6 positional operator matching incorrect sub document

document.js

db.bug.save({
  "_id" : ObjectId("53e29d8473636f0664000000"),
  "dimensions" : [
    {
      "_id" : ObjectId("53e29d8473636f0664010000"),
      "values" : []
    },
    {
      "_id" : ObjectId("53e29d8473636f06640b0000"),
      "values": []
    },
    {
      "_id" : ObjectId("53e29d8473636f06640c0000"),
      "values" : [
        {
          "_id" : ObjectId("53e29d8473636f06640e0000"),
          "weight" : 12
        },
        {
          "_id" : ObjectId("53e29d8473636f06640f0000"),
          "weight" : 11
        },
        {
          "_id" : ObjectId("53e29d8473636f0664100000"),
          "weight" : 3
        },
        {
          "_id" : ObjectId("53e29d8473636f0664110000"),
          "weight" : 17
        },
        {
          "_id" : ObjectId("53e29d8473636f0664120000"),
          "weight" : 35
        }
      ]
    },
  ]
});

mongo2.4-result.js

{
	"_id" : ObjectId("53e29d8473636f0664000000"),
	"dimensions" : [
		{
			"_id" : ObjectId("53e29d8473636f0664010000"),
			"values" : [ ]
		},
		{
			"_id" : ObjectId("53e29d8473636f06640b0000"),
			"values" : [ ]
		},
		{
			"_id" : ObjectId("53e29d8473636f06640c0000"),
			"values" : [
				{
					"_id" : ObjectId("53e29d8473636f06640e0000"),
					"weight" : 0 // Correct
				},
				{
					"_id" : ObjectId("53e29d8473636f06640f0000"),
					"weight" : 11
				},
				{
					"_id" : ObjectId("53e29d8473636f0664100000"),
					"weight" : 3
				},
				{
					"_id" : ObjectId("53e29d8473636f0664110000"),
					"weight" : 17
				},
				{
					"_id" : ObjectId("53e29d8473636f0664120000"),
					"weight" : 35
				}
			]
		}
	]
}

mongo2.6-result.js

{
	"_id" : ObjectId("53e29d8473636f0664000000"),
	"dimensions" : [
		{
			"_id" : ObjectId("53e29d8473636f0664010000"),
			"values" : [ ]
		},
		{
			"_id" : ObjectId("53e29d8473636f06640b0000"),
			"values" : [ ]
		},
		{
			"_id" : ObjectId("53e29d8473636f06640c0000"),
			"values" : [
				{
					"_id" : ObjectId("53e29d8473636f06640e0000"),
					"weight" : 12 // this value should have been updated
				},
				{
					"_id" : ObjectId("53e29d8473636f06640f0000"),
					"weight" : 11
				},
				{
					"_id" : ObjectId("53e29d8473636f0664100000"),
					"weight" : 0 // Incorrect sub document selected
				},
				{
					"_id" : ObjectId("53e29d8473636f0664110000"),
					"weight" : 17
				},
				{
					"_id" : ObjectId("53e29d8473636f0664120000"),
					"weight" : 35
				}
			]
		}
	]
}

update.js

db.bug.update({
  "_id":ObjectId('53e29d8473636f0664000000'),
  "dimensions._id":ObjectId('53e29d8473636f06640c0000'),
  "dimensions.2.values._id":ObjectId('53e29d8473636f06640e0000')
},{
  "$set":{
    "dimensions.2.values.$.weight": 0
  }
});

verify.js

db.bug.find({
  "_id":ObjectId('53e29d8473636f0664000000'),
  "dimensions._id":ObjectId('53e29d8473636f06640c0000'),
  "dimensions.2.values._id":ObjectId('53e29d8473636f06640e0000')
});

For mongodb 2.6 it looks like this should work...

db.bug.update({
  "_id":ObjectId('53e29d8473636f0664000000'),
  "dimensions._id":ObjectId('53e29d8473636f06640c0000')
},{
  "$set":{
  "dimensions.$.values.1.weight": 0
}
});

Indeed it's a complete different kind of updating :-(