jQuery Grid Plugin - jqGrid

Hi guys

I am having a tiny problem but first thanks Tony for the beautiful plugin.

I have setup a grid in which a cell background colour is set to a specific colour. In Firefox and other browsers everything is find, but in Internet Explorer the colour of the cell background I have set is not being rendered. Here is my code

jQuery("#tblScheduleDetail").jqGrid({
    url:'nothing',
    datatype: "json",
    height: 150, width: 850,
    colNames:['Appt time','Dur','Freq','SST','<img src="images/note.bmp">','<img src="images/paperclip.bmp">','Client','Address','Ess.','Associated Org Provider'],
    colModel:[{name:'col0',index:'col0'},
              {name:'col1',index:'col1'},
              {name:'col2',index:'col2'},
              {name:'col3',index:'col3'},
              {name:'col4',index:'col4'},
              {name:'col5',index:'col5'},
              {name:'col6',index:'col6'},
              {name:'col7',index:'col7'},
              {name:'col8',index:'col8'},
              {name:'col9',index:'col9'}],
    rowNum:200,
    mtype: "POST",
    rownumbers: false,
    gridview: true,
    pager: '#pager',
    sortname: '',
    viewrecords: true,
    sortorder: "asc",
    caption: "Schedule Detail"
});
var data = [ {col1:"col1,row1", col2:"col2,row1",col3:"col3,row1",col4:"col4,row1"},
            {col1:"col1,row2", col2:"col2,row2",col3:"col3,row2",col4:"col4,row2"},
            {col1:"col1,row3", col2:"col2,row3",col3:"col3,row3",col4:"col4,row3"},
            {col1:"col1,row4", col2:"col2,row4",col3:"col3,row4",col4:"col4,row4"}];
for(var i = 0; i <= data.length; i ++){
    jQuery("#tblScheduleDetail").addRowData(i+1,data[i]);
}
jQuery("#tblScheduleDetail").setCell(1,'col4','',{'background-color':'yellow'});

I may have missed something, can someone help please