jQuery Grid Plugin - jqGrid

I have a grid with search toolbar. One of my columns has a dropdown box as search field type and. The column is defined like this:

{ "searchoptions": { sopt: ['eq', 'ne'], defaultValue: "OPEN", "dataUrl": _baseUrl + "Ticket/GetStatusList", "buildSelect": buildDropDown}, "index": "Status", "name": "Status", "stype": "select" },

My problem is that the default value is not used to filter the map at startup. It is correctly selected in the dropdown, but the filter is not applied. I need to manually change the value of the dropdown to make it affect the filter (postData).

What I think is strange is that I have other columns that uses defaultValue, and they work fine (values are correctly applied to the filter when it goes to the server to fetch data). I tried changing the type of the dropdownbox back to a normal input field, and then it worked for that column as well.

It seems to me there is a problem with setting default search values for dropdown boxes. Does anyone know why, and is there a simple solution to my problem?

Thanks in advance.