使用AngularFire 0.5.0 - $移除项目无效

I just wanted to work more on my first little Angular project and I updated AngularFire from 0.3.0 to 0.5.0 and nothing really works anymore. I was able to get the database access back and also to add items to my list. But the remove function doesn't work anymore. Before I udpated AngularFire, I used splice(index,1) to remove an item. I also tried to use the new $remove from 0.5.0 but it just removes all items from the list, even I add a key. I just wanted to work more on my first little A