Custom activity which is hold within another activity will be cloned by expanding to detail view

Question

Hi there,

i have a problem which is related to my custom activity in .net Workflow 4.

My custom activity XActivity can hold other activities. Everything works fine even the displaying and executing.

Except when i doublecklick on a custom activity for getting the detail view (expanding). Then the activity which is a child activity will be executed more than one time. In fact every time i click on expand the number of execution times will be doubled or something like this.

<sad:WorkflowItemsPresenter Name="myWorkflowElements"  Grid.Row="1" Items="{Binding Path=ModelItem.ChildActivities}" Drop="WorkflowItemsPresenter_Drop">

            <sad:WorkflowItemsPresenter.SpacerTemplate>
                <DataTemplate>
                    <TextBlock Width="150" Height="20" Text="Drop xxx Here" Foreground="Gray" />
                </DataTemplate>
            </sad:WorkflowItemsPresenter.SpacerTemplate>
            <sad:WorkflowItemsPresenter.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Vertical" Margin="16"/>
                </ItemsPanelTemplate>
            </sad:WorkflowItemsPresenter.ItemsPanel>

        </sad:WorkflowItemsPresenter>

I dont know what is wrong there.

Perhaps there is something wrong with the connection to the activity.