posting array of checkboxes in a dragable UI: not getting posted

I am using array of checkboxes in my draggable UI, so that we can change the row order by drag and drop. When I drag the bottom entries to top I am not getting all the checked checkboxes on POST.

print_r($this->input->post("dconf_check"));

<input type="checkbox" name="dconf_check[]" value="18" checked="checked" id="dconf_18" title="name">
<input type="checkbox" name="dconf_check[]" value="13" checked="checked" id="dconf_13" title="name">
<input type="checkbox" name="dconf_check[]" value="19" checked="checked" id="dconf_19" title="name">