Commented Unassigned: CheckComboBox loses values when scrolled out of view [21917]

I am using a CheckComboBox within a ListView/GridView column, defined as follows...
```
<GridViewColumn Header="Surcharges">
<GridViewColumn.CellTemplate>
<DataTemplate>
<et:CheckComboBox Delimiter=" " DisplayMemberPath="PalletNetworkSurchargeCode" ItemsSource="{Binding Path=SurchargeOptions}" MinWidth="100" SelectedValue="{Binding Path=Surcharges}" ValueMemberPath="PalletNetworkSurchargeCode" Width="100" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
```

Within the View Model, SurchargeOptions is a List<PalletNetworkSurcharge>, PalletNetworkSurcharge.PalletNetworkSurchargeCode is a String, and SurchargeOptions is also a String.

If the user scrolls the list (quickly), or resizes the form in such a way that one or more items in the list is no longer visible, when that item is made visible again (either by more scrolling or more resizing) any items selected in the CheckComboBox are no longer selected and the clearing of the selected items is also reflected in the bound "SelectedValue".

Can you please help. Am I missing something within the Xaml or is there a problem with the control?

Thanks.

Martin.
Comments: ** Comment from web user: MartinRobins **

Most users are running on Windows 7, though I have reproduced the problem on Windows 8.1 too.

I will put together an application to reproduce the error as soon as I get a chance; probably over the weekend but I will try and do it this afternoon (UK). I cannot post the entire solution as it is simply too big (and of course proprietary).

Thanks.