CameraRoll api does not return all photos in an album

Question

I am using CameraRoll api (getPhotos) to extract images from a specific album. Unfortunately, when I call getPhotos (with any combination of the first: number) params, I do not always get all the photos in the album.

I usually have to make getPhotos call several times (by pressing the g button that I added to the application) to request all the snapshots. I am wondering if this is due to the cursor attribute returned by the callback after a successful getPhotos request.