Using ember-idx-tabs panel inside an each block

I'm trying to use the ember-idx-tabs addon on my app. My associations are as follow:

Practice ->* PracticePart -> Part

On the Practice show template I would like to show a tab for each PracticePart. I came up with

{{#em-tabs selected-idx=tab_idx}}
  {{#em-tab-list}}
    {{#each practicePart in practiceParts}}
      {{#em-tab}}{{practicePart.part.symbol}}{{/em-tab}}
    {{/each}}
  {{/em-tab-list}}

  {{#each practicePart in practiceParts}}
    {{#em-tab-panel}}
      {{practicePart.part.symbol}}
    {{/em-tab-panel}}
  {{/each}}
{{/em-tabs}}

The problem is I'm getting only the tabs, the panels are all hidden (display: none). If I dont iterate, but instead add some em-tab-panels manually they are shown correctly and behave as expected.

I'm guessing its something I'm not doing well, cause I'm just learning ember.js, I'd appreciate any help!!!