Hi

I'm attaching a sample project where you can see this behavior and here is the brief (at least I hope so) description:

I have model with two properties e.g. FirstList and SecondList both of type BindingList<DataObject> and two properties FirstSelected and SecondSelected both of type List<object>.

On my form I have two UltraCombos with multiselection which DataSource properties are bound to FirstList and SecondList and whose Value properties are bound to FirstSelected and SecondSelected.

In my model I have some code that clears SecondList and fills it with respective elements if FirstSelected is changed.

The problem is when I first check some values in first combo then check some values in second combo and then uncheck values in first combo I expect the second combo to be cleared.

But instead I get the exception {"Value cannot be null.\r\nParameter name: key"} with stack trace:

   at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
   at Infragistics.Win.UltraWinGrid.CheckedRowsCollection.VerifyCollection()
   at Infragistics.Win.UltraWinGrid.CheckedRowsCollection.Equals(List`1 values)
   at Infragistics.Win.UltraWinGrid.CheckedListSettings.OnRowsCollectionDataChanged(Object sender, DataChangedEventArgs e)
   at Infragistics.Win.UltraWinGrid.RowsCollection.FireDataChanged(DataChangedEventArgs args)
   at Infragistics.Win.UltraWinGrid.RowsCollection.OnListChanged(Object sender, ListChangedEventArgs e)
   at System.ComponentModel.ListChangedEventHandler.Invoke(Object sender, ListChangedEventArgs e)
   at System.Windows.Forms.BindingSource.OnListChanged(ListChangedEventArgs e)
   at System.Windows.Forms.BindingSource.ResetBindings(Boolean metadataChanged)
   at System.Windows.Forms.BindingSource.SetList(IList list, Boolean metaDataChanged, Boolean applySortAndFilter)
   at System.Windows.Forms.BindingSource.ParentCurrencyManager_CurrentItemChanged(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Windows.Forms.CurrencyManager.OnCurrentItemChanged(EventArgs e)
   at System.Windows.Forms.CurrencyManager.List_ListChanged(Object sender, ListChangedEventArgs e)
   at System.Windows.Forms.BindingSource.OnListChanged(ListChangedEventArgs e)
   at System.Windows.Forms.BindingSource.ListItem_PropertyChanged(Object sender, EventArgs e)
   at WindowsFormsApplication1.Model.OnSecondSelectedChanged() in C:\Users\chapand-a\documents\visual studio 2010\Projects\WindowsFormsApplication1\WindowsFormsApplication1\Model.cs:line 94
   at WindowsFormsApplication1.Model.set_SecondSelected(List`1 value) in C:\Users\chapand-a\documents\visual studio 2010\Projects\WindowsFormsApplication1\WindowsFormsApplication1\Model.cs:line 84

Could something be done about it?

Please look at the attached solution for all details. Libraries versions are 10.2