I am using the latest ultrawebgrid & asp.net3.5

I have an object data source(list), bind it to a simple grid using InitializeDS(Not in a WARP, AJAX enabled )

The grid has check boxes, I am handling updatecell to track the state of the checks.

I  update the Database in updatecell depending on the state of the checks and have to reload the grid.

I am trying to assign the updated DS to the grid and call DataBind in UpdateCell.

Running into the following exception:

[NullReferenceException: Object reference not set to an instance of an object.]
   Infragistics.WebUI.UltraWebGrid.UltraWebGrid.UpdateDBRow(UltraGridRow row, UltraGridRow oldRow) +155
   Infragistics.WebUI.UltraWebGrid.UltraWebGrid.ProcessChanges(StateChanges stateChanges, Boolean fireEvents) +1559
   Infragistics.WebUI.UltraWebGrid.UltraWebGrid.RaisePostDataChangedEvent() +161
   System.Web.UI.Page.RaiseChangedEvents() +165
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1485

I tried setting the DS to null and binding to a null DS( came across these in the forums)

Any thoughts or ideas why this is happening? 

thanks,

sam