JQGrid with ASP.NET MVC causing call to default action twice

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ASP.NET

MVC

jQuery

JQGrid

I am using JQGrid in ASP.NET MVC and initializing the grid in document ready as below

jQuery("#grid1").jqGrid({
    colNames: ['Col1', 'Col2'],
    colModel: [
                { name: 'Col1', index: 'Col1', width: 2, sortable: false },
                { name: 'Col2', index: 'Col2', width: 2, sortable: false }
              ],
    onSelectRow: function (currid) {
        //doing some thing
    },
    autowidth: true,
    shrinkToFit: false,
    height: '100',
    width: '100%',
    rowNum: 2,
    pgtext: "",
    pgbuttons: false,
    viewrecords: true,
    imgpath: '@Url.Content("~/Content/images/jqgrid/")', 
    toolbar: false,
    gridComplete: function () {
        $("tr.jqgrow:odd").css("background", "#DDDDDC");
    }
});

when the ready is fired and at end it does a server call to default page action as below

controller/action?_search=false&nd=1375859081229&rows=2&page=1&sidx=&sord=asc

I have replaced the controller and action name in the above url.

why is this behavior happening? and how to avoid this behavior?