title: Two-way binding does not work for header fields
body: <p>I am using <code>OData V2 Model</code> and I have set default binding Mode to <code>TwoWay</code>, but fields on header level do not get changed in the model, and when I try to submit, <code>model</code> has no changes and do not submit. But if I change some field in a <code>table</code> (<code>aggregation</code>), <code>model</code> get changes and submit works.</p>
  
  <p>Any idea why <code>TwoWay</code> binding mode works in only <code>aggregations</code>?</p>
  
  <p>Any help is welcome.</p>