population regression in 3.6.5

[aheckmann]

var CommentSchema = new Schema({
 creatorId : {
           type : ObjectId,
                ref : 'User',
   },
      body : {
                type : String
   },
});
var Comment = db.model('Comment', CommentSchema);


//User
var UserSchema = new Schema({
       name : {
                type : String
   }
});

var User = db.model('User', UserSchema);


var user = new User({ name: 'Jack'});
user.save( function( error, user){
 var comment = new Comment({
             creatorId: user._id,
            body: 'Comment to you'
  });
     comment.save( function(error, comment){
         var comment2 = new Comment({
                    creatorId: user._id,
                    body: 'Comment to you'
          });
             comment2.save( function(error, comment2){

                        Comment.find()
                  .select( 'creatorId')
                  .select('-_id')//The condition to reproduce
                    .populate('creatorId')
                  .exec( function( error, comments){
                              console.log( comments[0].creatorId.name);//undefined
                        });

                });
     });
})

see https://groups.google.com/d/msg/mongoose-orm/Hvz2sixp6q0/2pVZOY3b2pgJ