I'm trying to change the content of the list in xamComboEditor based on the value entered in another column. When I do that and click off the record being edited I get the following exception.

Message: Unhandled Error in Silverlight Application Operation is not valid due to the current state of the object.   at System.Windows.Data.BindingExpression.UpdateSource()
   at Infragistics.Controls.Grids.CellControl.EvaluateEditingBindings()
   at Infragistics.Controls.Grids.XamGrid.ExitCellFromEditModeInternalRow(Boolean cancel)
   at Infragistics.Controls.Grids.XamGrid.ExitEditModeInternal(Boolean cancel)
   at Infragistics.Controls.Grids.XamGrid.SetActiveCell(CellBase cell, CellAlignment alignment, InvokeAction action, Boolean allowSelection, Boolean setFocus, Boolean scrollIntoView)
   at Infragistics.Controls.Grids.XamGrid.SetActiveCell(CellBase cell, CellAlignment alignment, InvokeAction action, Boolean allowSelection, Boolean scrollIntoView)
   at Infragistics.Controls.Grids.XamGrid.SetActiveCell(CellBase cell, CellAlignment alignment, InvokeAction action, Boolean allowSelection)
   at Infragistics.Controls.Grids.Cell.OnCellMouseDown(MouseEventArgs e)
   at Infragistics.Controls.Grids.XamGrid.XamWebGrid_MouseLeftButtonDown(Object sender, MouseButtonEventArgs e)
   at MS.Internal.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)

Thank you,

Eugene