spotify stop run after 2 tracks

[Totek]

Hey!

I have iPhone 4 and last IOS-version  on it and i have last version of Spotify Application too. But i have problem with playing. After 2 or 4 tracks this go off. And i can't play. I must restart my app and play last track again. But this older tracks "deleted" in the played tracks.

Someone have same problems?

Or is it when this phone shift from 3g to WiFi and back to 3g? Or what?

I don't have this problem with my iPad air.

Please... Help me! I don't like this problem.