setCellData in response causes grid to lose focus in IE

In the following example, making changes to any cell in columns 3 or 4 sets the that cellData to "!". The problem is that once that happens I lose focus on the grid and the keybord no longer ineracts with the grid. I need to click on the grid to regain focus. It actually reponds to the first keystroke, but anything after that is ignored. I am using IE 6.0.2900.2180 on XP-SP2. The problem does not appear in mozilla.

<script>

var grid_gridObj_data = [[ "2081175","Test1","Test2","10","6"],[ "2081179","test3","test4","1","8"] ];
var grid_gridObj_columns = ["Key1","Key2","Key3","Number1","Number2"];

var gridObj = new AW.UI.Grid;
gridObj.setColumnCount(15);
gridObj.setRowCount(2);
gridObj.setHeaderText(grid_gridObj_columns);
gridObj.setCellData(grid_gridObj_data);
gridObj.setCellEditable(true,3);
gridObj.setCellEditable(true,4);
gridObj.onCellValidated = function(text, column, row){
var r = new AW.HTTP.Request;
r.setURL("updateGrid.jsp");
r.setRequestMethod("POST");
r.setParameter("column", column);
r.setParameter("row", row);
r.setParameter("fieldValue", text);
r.response = function(data){
gridObj.setCellData(data, column, row);
}
r.request();

}
document.write(gridObj);
</script>


updategrid.jsp:
<%
out.clear();
out.write( "!" );
if(true) return;
%>