unset on the higher leve item fails

[cooolbasha]

Hi, if there is a model with fields model = name: 'test' kart: r1: [4,4,o] r2:[8,8] if I call model.unset('kart') ..it does update the model. but the model changes does not trigger to model binder..if it is done 1 at a time say model.unset('kart.r1') works