Sharepoint Web Service Query ignoring Query Paramaters

I am trying to query Sharepoint 2010 via the Web Service using CalmQuery.

I created the calmQuery through a calmquery buidler, so im pretty sure the query is correct, however the GetListItems() ignore this query and just gets every item in the list:

here is my code:

            /* Query */
        XmlDocument calmDocument = new XmlDocument();
        XmlNode camlNode = calmDocument.CreateElement("Query");

        camlNode.InnerText = "<Where>" +
                            "<Eq>" +
                             "<FieldRef Name='Office_x0020_Staff' />" +
                             "<Value Type='Boolean'>Yes</Value>" +
                            "</Eq>" +
                            "</Where>";

        XmlNode Test = GetService().GetListItems("Staff", null, camlNode, null, null, null, null);

        for (int i = 0; i < Test.ChildNodes[1].ChildNodes.Count; i++)
        {
            if (Test.ChildNodes[1].ChildNodes[i].Attributes != null)
            {
                MessageBox.Show(Test.ChildNodes[1].ChildNodes[i].Attributes["ows_Title"].InnerText;                                            
            }

        }