I'm using a customer autocomplete textbox (http://wpfactb.codeplex.com) in XamTextEditor EditTemplate (v12.1), and all is working fine except when I use the tab key to navigate to the next cell, the autocomplete's dropdown doesn't close.  It does close when I click on the next cell.  I realize I'm not giving you much info about the autocomplete control, but can you think of anything I might be doing wrong using the following EditTemplate:

<Style TargetType="igEditors:XamTextEditor">

    <Setter Property="Template">

      ...

    </Setter>

    <Setter Property="EditTemplate">

        <Setter.Value>

            <ControlTemplate TargetType="igEditors:XamTextEditor">

                <actb:AutoCompleteTextBox x:Name="PART_FocusSite" BorderThickness="0" MaxLength="50">

                    <actb:AutoCompleteTextBox.AutoCompleteManager>

                        <actb:AutoCompleteManager>

                            <actb:AutoCompleteManager.DataProvider>

                                <local:PartDataProvider/>

                            </actb:AutoCompleteManager.DataProvider>

                        </actb:AutoCompleteManager>

                    </actb:AutoCompleteTextBox.AutoCompleteManager>

                </actb:AutoCompleteTextBox>

            </ControlTemplate>

        </Setter.Value>

    </Setter>

</Style>