Issue with Google chrome and Firefox

Hi everyone, I'm working in Project Server 2010, and we add a javascript into Timesheet page to add some fuctionality to the timesheet gird, in IE works great but in Chrome and Firefox don't work. This is the issue we add this code on javascript using a reference to jquery

PJ.AddGridSatelliteInitializationNotifier
    (
        function (satellite) {

            if (PJ.TimesheetSatellite != null) {
                satellite = PJ._NotifySatelliteInitComplete.arguments[0];
                _satellite = satellite;

                _grid = satellite.GetJsGridControlInstance();
                _grid.AttachEvent(SP.JsGrid.EventType.OnPropertyChanged, OnPropertyChanged);

                _grid.parentNode.onafterupdate = function () {
                   AddExtensionLinesAndColumns();
                }
            }
        }
    );

In IE when we debug the code when is finish of excute this code, fires the on after update handler of the grid, and runs every things else good, but when we debug in Chrome don't fire the on after update handler and I don't know why is not doing that, can somebody helps me.

Thanks.

.Net Developer and SharePoint programmer