Angular2 Http module runs correctly on alpha.47 but it's failing on alpha.48.

page1.ts

import {Component} from 'angular2/angular2'
import {Http, Response, HTTP_PROVIDERS} from 'angular2/http'
import _ from 'lodash'

@Component({
  selector: 'my-page1',
  template: `
    <ul>
      <li *ng-for="#card of cards">{{card.title}}</li>
    </ul>
  `,
  providers: [HTTP_PROVIDERS]
})
export class Page1 {
  cards: Card[] = [];
  constructor(public http: Http) {     
  }
  
  loadCards(searchWord: string = '') {
    (async() => {
      let cards = await this.http.get('/cards.json')
        .map((res:Response) => res.json() as Card[])
        .toPromise(Promise);
      if (searchWord) {
        const words = _.words(searchWord);
        words.forEach(word => {
          cards = _.filter(cards, card => {
            return card.title.indexOf(word) > -1 || card.body.indexOf(word) > -1;
          });
        });
      }
      this.cards = cards;
    })();
  }  
}