ember.js - Ember property doesn't update properly with multiple dependencies -

my property sum depends on 3 different properties (inside model). have other property depends on sum. iszero , sum have binding in template {{iszero}} {{sum}}.

this simplified code:

sum: function () {      console.log('sum is', this.get('p1') + this.get('p2') + this.get('p3'));      return this.get('p1') + this.get('p2') + this.get('p3'); }.property('p1', 'p2', 'p3'),  p1: function () {     console.log('update p1');     return _data.p1; }.property('data'),  p2: function () {     console.log('update p2');     return _data.p2; }.property('data'),  p3: function () {     console.log('update p3');     return _data.p3; }.property('data'),  data: {},  _data: {p1: 1, p2: 2, p3: 3},  iszero: function () {     console.log('sum in iszero is', this.get('sum'));     return this.get('sum') === 0; }.property('sum'),  updatedata: function () {     this._data = {p1: 0, p2: 0, p3: 0};     this.notifypropertychange('data'); }  

some times, when update data, sum , iszero not correctly updated. if call updatedata(), these prints in console:

> update p1 > sum 5 > sum in iszero 5 > update p2 > update p3 > sum 0 

as can see iszero not updated anymore , sum updates twice. template display iszero false , sum 0. know code looks crazy closest can show problem. tried reproduce in ember jsbin, unfortunately works correctly in there.

anyone have ideia why happening?

ps.: updatedata call inside ember run loop. i'm using ember version 1.9.1.