IronRouter and Meteor Subscription Problems

publish.js

Meteor.publish('travelRequests', function() {
  return TravelRequests.find({}, {
    fields: {
      'first_name': true,
      'last_name' : true,
      'email'     : true,
      'depart_on' : true,
      'return_on' : true,
      'status'    : true
    }
  });
});

Meteor.publish('singleTravelRequest', function(id) {
  return TravelRequests.find({_id: id});
});

router.js

Router.configure({
  layoutTemplate: 'layout',
  notFoundTemplate: '404',
  loadingTemplate: 'loading'
});


Router.map(function() {

  this.route('home', {
    path: '/',
    template: 'travel',
    controller: 'TravelController',
    action: 'index'
  });

  this.route('newTravel', {
    path: '/travel/new',
    controller: 'TravelController',
    action: 'new'
  });

  this.route('editTravel', {
    path: '/travel/:_id/edit',
    controller: 'TravelController',
    action: 'edit'
  });
  
  // this was switched between ShowTravelController, and TravelController#show for each repective case
  this.route('showTravel', {
    path: '/travel/:_id',
    controller: 'ShowTravelController'
  });

  this.route('travel', {
    path: '/travel',
    controller: 'TravelController',
    action: 'index'
  });

});

ShowTravelController.js

// TravelController.show was commented out when using this controller
ShowTravelController = ApplicationController.extend({
	waitOn: function() {
		var id = this.params._id;
		return [Meteor.subscribe('singleTravelRequest', id)];
	},

	action: function() {
	  // tried this one too
		// this.waitOn = Meteor.subscribe('singleTravelRequest', this.params._id);
		this.data = TravelRequests.findOne({_id: this.params._id});
		this.render();
		this.render('travelNav', {to: 'topNav'});
	}
});

TravelController.js

TravelController = ApplicationController.extend({

  waitOn: function() {
    var id = this.params._id;
    return [Meteor.subscribe('travelRequests'), Meteor.subscribe('singleTravelRequest', id)];
  },

  index: function() {
    this.renderTravel();
  },

  new: function() {
    this.renderTravel();
  },
  // this show action is commented out when using ShowTravelController
  show: function() {
    this.data = TravelRequests.findOne({_id: this.params._id});
    this.renderTravel();
  },

  edit: function() {
    this.data = TravelRequests.findOne({_id: this.params._id});
    this.renderTravel();
  },

  renderTravel: function() {
    this.render();
    this.render('travelNav', {to: 'topNav'});
  }

});