My situation is that I have a user control inside the group header template of the outlook bar.  This user control has a bunch of controls that it manages as well.  The outlook bar is bounded to a wcf service and passes a value to the user control, the user control then uses that value and gets it's own values from the wcf service.  The issue I'm having is which ever group header I select first all the other group content is the same as that one. Here the test I used to get this issue:

WCF Service:

[OperationContract]
public List<GroupHeader> GetGroups()
{
 List<GroupHeader> groups = new List<GroupHeader>();
 for (int i = 0; i < 10; i++)
 {
  groups.Add(new GroupHeader() { ID = i, Name = "Group " + i.ToString() });
 }

 return groups;
}
[OperationContract]
public List<GroupItem> GetItems(int groupID)
{
 List<GroupItem> items = new List<GroupItem>();

 for (int i = 0; i < 10; i++)
 {
  if (i == groupID)
  {
   for (int j = 0; j < 15; j++)
   {
    items.Add(new GroupItem() { ID = j, Name = "Group " + i.ToString() + " - Item " + j.ToString() });
   }
   break;
  }
 }

 return items;
}

[DataContract]
public class GroupHeader
{
 [DataMember]
 public int ID { get; set; }
 [DataMember]
 public string Name { get; set; }
}

[DataContract]
public class GroupItem
{
 [DataMember]
 public int ID { get; set; }
 [DataMember]
 public string Name { get; set; }
}

Main Outlook bar Control Xaml:

<igOB:XamWebOutlookBar x:Name="MainOutlookBar" Width="300" Height="500">
 <igOB:XamWebOutlookBar.GroupHeaderTemplate>
  <DataTemplate>
   <TextBlock Text="{Binding Path=Name}"></TextBlock>
  </DataTemplate>
 </igOB:XamWebOutlookBar.GroupHeaderTemplate>
 <igOB:XamWebOutlookBar.GroupContentTemplate>
  <DataTemplate>
   <medscc:GroupItem GroupID="{Binding Path=ID}" />
  </DataTemplate>
 </igOB:XamWebOutlookBar.GroupContentTemplate>
</igOB:XamWebOutlookBar>

Main Outlook bar Control Code Behind:

public MainOutlookBar()
{
 ServiceClient.GetGroupsCompleted += new EventHandler<GetGroupsCompletedEventArgs>(ServiceClient_GetGroupsCompleted);
 InitializeComponent();

 ServiceClient.GetGroupsAsync();
}

void ServiceClient_GetGroupsCompleted(object sender, GetGroupsCompletedEventArgs e)
{
 if (e.Error == null)
 {
  MainOutlookBar.GroupsSource = e.Result;
 }
}

User Control Xaml:

 <ListBox x:Name="GroupItems">
 <ListBox.ItemTemplate>
  <DataTemplate>
   <TextBlock Text="{Binding Name}"></TextBlock>
  </DataTemplate>
 </ListBox.ItemTemplate>
</ListBox>

User control Code behind:

#region Private Members
private ServiceClient ServiceClient;
#endregion

public static readonly DependencyProperty GroupProperty =
 DependencyProperty.Register("GroupID",
 typeof(int),
 typeof(GroupItem),
 new PropertyMetadata(new PropertyChangedCallback(OnPropertyChanged)));

public int GroupID
{
 get { return (int)GetValue(GroupProperty); }
 set
 {
  SetValue(GroupProperty, value);
  ServiceClientt = new ServiceClient();
  ServiceClient.GetItemsCompleted += new EventHandler<GetItemsCompletedEventArgs>(ServiceClient_GetItemsCompleted);
  ServiceClient.GetItemsAsync(value);
 }
}

public GroupItem()
{
 
 InitializeComponent();
}

void ServiceClient_GetItemsCompleted(object sender, GetItemsCompletedEventArgs e)
{
 if (e.Error == null)
  GroupItems.ItemsSource = e.Result;
}

public static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
 GroupItem groupItem = (GroupItem)d;
 groupItem.GroupID = (int)e.NewValue;
}