Which version of bootstrap are you using? The early versions of Bootstrap 3 (3.0, 3.0.1) didn't work with this functionality.
col-md-offset-0 should be working as seen in this bootstrap example found here (http://getbootstrap.com/css/#grid-responsive-resets):
<div class="row">
<div class="col-sm-5 col-md-6">.col-sm-5 .col-md-6</div>
<div class="col-sm-5 col-sm-offset-2 col-md-6 col-md-offset-0">.col-sm-5 .col-sm-offset-2 .col-md-6 .col-md-offset-0</div>
</div>