Les chansons sont scrobblées des le début de la lecture, hors ce n'est pas le pas le comportement attendu pour les applications utilisant Last.fm

Voici les recommendations de last.fm :

3.1 When to Submit

The client should monitor the user's interaction with the music playing service to whatever extent the service allows. In order to qualify for submission all of the following criteria must be met:

1. The track must be submitted once it has finished playing. Whether it has finished playing naturally or has been manually stopped by the user is irrelevant.
2. The track must have been played for a duration of at least 240 seconds or half the track's total length, whichever comes first. Skipping or pausing the track is irrelevant as long as the appropriate amount has been played.
3. The total playback time for the track must be more than 30 seconds. Do not submit tracks shorter than this.
4. Unless the client has been specially configured, it should not attempt to interpret filename information to obtain metadata instead of using tags (ID3, etc).


http://www.lastfm.fr/api/submissions