ToolTip only shows on “Click”- google charts

Question

Friends, After several hours of searching for an answer I am unable to fix my problem. I am working with latest jQuery and Google's API visualizations.

On page load, the ColumnChart renders properly. When you mouseover the bars it shows a hover-ish event being detected (highlighting of the edges - showing that mouseover is working). However, it doesn't show the tooltip box with the information.

Now when you click on the bar, the tooltip DOES appears. I never had this problem before. I thought the default for the hovering was to show the tool tip.

Any help is greatly appreciated.

Here is my .JS code:

$(document).ready(function()    {


     $.post('presu.php', function ( data ) {    
        var data = new google.visualization.DataTable(JSON.parse(data)); 
        var view = new google.visualization.DataView(data);
                    view.setColumns([0, 
                                        {label: data.getColumnLabel(1),type: 'number', calc: function (dt, row) {
                                            return {v: dt.getValue(row, 1) / 1000000, f: dt.getFormattedValue(row, 1)};
                                        }},
                                        {label: data.getColumnLabel(2),type: 'number', calc: function (dt, row) {
                                            return {v: dt.getValue(row, 2) / 1000000, f: dt.getFormattedValue(row, 2)};
                                        }},
                                        {label: data.getColumnLabel(3),type: 'number', calc: function (dt, row) {
                                            return {v: dt.getValue(row, 3) / 1000000, f: dt.getFormattedValue(row, 3)};
                                        } 
                    }]);

        var columnChart = new google.visualization.ColumnChart(document.getElementById('mdo'));
            columnChart.draw(view,
                     {title:"Cells",
                        width:600, 
                        height:400,
                        tooltip: {isHtml: true},
                        isStacked:true,
                        legend:'bottom',
                        tooltip:{},
                        focusTarget:"category"
                });
     });

})

Thanks in advance.

Thanks