jQuery Grid Plugin - jqGrid

I'm trying to use the integrated toolbar search with "dataurl", but there's a bug and the select box doesn't get inserted in the right column...

There's a prototype on this url to see my code:

http://dev.sxx.com/temp/jqgrid.html

My config is generated from a yaml file that is quite simple:

test:
  caption: List of Campaigns
  colNames:
    A
    B
    C
  colModel:
    - name: id
      index: id
    - name: p.name
      index: p.name
      stype: select
      searchoptions:
        dataUrl: /admin/grid/htmlgetprojectselect
    - name: C
  pager: 'pager'
  filtertoolbar: true

Am I doing anything wrong or is this a known bug?

Thanks