Datagrid Item Renderer not displaying correct data

Question

I have a datagrid that displays information from a web service, which is refreshed every 60 seconds.
When the status is no 0 for a line a corresponding color is used to fill in the background.  I created a Item Renderer to fill in the background color.
When the table is initially created, the colors are correct.  After the data is refreshed, then the background color value is carried over to the next row.
The Spark DataGrid works better than the MX AdvancedDateGrid or DataGrid.  This was working in Flex 3, but I used an function which replaced the DataGridColumn that doesn't work in Flex 4.
protected function init(event:FlexEvent):void
                var showBackground:Boolean = false;
                var backgroundColor:uint = new uint();
                var labelTextColor:uint = new uint();
                var dgListData:DataGridListData = listData as DataGridListData;
                var dataGrid:DataGrid = dgListData.owner as DataGrid;
                // comment this out if you want to see the background over the
                // selection and highlight indicators
                if (dataGrid.isItemSelected(data) || dataGrid.isItemHighlighted(data))
                    // clear the background so you can see the selection/highlight colors
                    showBackground = false;
                    return;
                switch(data["MessageLevel"])
                    case 0:
                        showBackground = false;
                        backgroundColor = 0xFFFFFF;
                        labelTextColor = 0x000000;
                        break;
                    case 1:
                        showBackground = true;
                        backgroundColor = 0x00FF00;  // light green
                        labelTextColor = 0x000000;
                        break;
                    case 2:
                        showBackground = true;
                        backgroundColor = 0x015F00; // dark green
                        labelTextColor = 0xFFFFFF;
                        break;
                    case 3:
                        showBackground = true;
                        backgroundColor = 0xFDFF00; // yellow
                        labelTextColor = 0x000000;
                        break;
                    case 4:
                        showBackground = true;
                        backgroundColor = 0x7F6E3F; // tan
                        labelTextColor = 0xFFFFFF;
                        break;
                    case 5:
                        showBackground = true;
                        backgroundColor = 0xFF8A00; // orange;
                        labelTextColor = 0x000000;
                        break;
                    case 6:
                        showBackground = true;
                        backgroundColor = 0xFFDFE0; // rose
                        labelTextColor = 0x000000;
                        break;
                    case 7:
                        showBackground = true;
                        backgroundColor = 0xFF0000; //red
                        labelTextColor = 0xFFFFFF;
                        break;   
                if(showBackground) {
                    var bgFill:SolidColor = new SolidColor();
                    bgFill.color = backgroundColor;
                    dataContainer.setStyle("backgroundColor",backgroundColor);
                    lblData.setStyle("color", labelTextColor);

Answer 1

I added an "else" statement to make sure that a color was always added, even if the level was 0.  I also added a backgroundAlpha style to both, to turn the value off or on.
So far, this seems to be the solution.
if(showBackground) {
var bgFill:SolidColor = new SolidColor();
bgFill.color = backgroundColor;
dataContainer.setStyle("backgroundColor",backgroundColor);
labelDisplay.setStyle("color", labelTextColor);
dataContainer.setStyle("backgroundAlpha",1);
} else {
dataContainer.setStyle("backgroundColor",backgroundColor);
labelDisplay.setStyle("color", labelTextColor);
dataContainer.setStyle("backgroundAlpha",0);