Problems with pagination getting data with http

I have a problem using the pagination in my table. This is my code:

```
ngOnInit() {
this.representativesS.getRepresentatives()
.subscribe(
data => {
this.representatives = data;
this.representativesSource = new LocalDataSource(this.representatives);
},
error => {
console.log(error)
}
);
}
```
The function `this.representativesS.getRepresentatives()` is doing a http request and returns an array with objects `this.representatives`, after that I get the data to show into the table and then it shows wrong without numbers between the arrows, like << >>. But I've tried to show the data directly with no http request (it's a static array) and the pagination works fine. So it seems there is a problem combining the http with the ng2-smart-table. Any ideas? Thanks!