How can I remove blank lines from a TreeView bound to an XML document?

Question

After going through StackOverflow yesterday, I found a solution to the problem of binding an XML document to a treeview in an answer here. It worked like a charm, with one problem: now I have a blank line at the top of each node, one for each immediate child it has.

I'm at a loss as to how to get rid of it.

Here's the XML:

<Window.Resources>
    <outboundInterfaceTestService:TrueToVisibleConverter x:Key="TrueToVisibleConverter" />
    <outboundInterfaceTestService:TrueToCollapsedConverter x:Key="TrueToCollapsedConverter" />
    <HierarchicalDataTemplate x:Key="NodeTemplate">
        <TextBlock x:Name="text" Text="" />
        <HierarchicalDataTemplate.ItemsSource>
            <Binding XPath="child::node()|attribute::*" />
        </HierarchicalDataTemplate.ItemsSource>
        <HierarchicalDataTemplate.Triggers>
            <DataTrigger Binding="{Binding Path=NodeType}" Value="Text">
                <Setter TargetName="text" Property="Foreground" Value="Red" />
                <Setter TargetName="text" Property="Text" Value="{Binding Path=Value}" />
            </DataTrigger>
            <DataTrigger Binding="{Binding Path=NodeType}" Value="Element">
                <Setter TargetName="text" Property="Text" Value="{Binding Path=Name}" />
            </DataTrigger>
        </HierarchicalDataTemplate.Triggers>
    </HierarchicalDataTemplate>
</Window.Resources>

<!-- snip! -->
<!-- later on, the TreeView itself -->
<TreeView Name="ContentTree"
            Grid.Row="3"
            ItemsSource="{Binding Path=SelectedItem.ContentXmlDoc}"
            ItemTemplate="{StaticResource NodeTemplate}"
            Visibility="{Binding Path=SelectedItem.IsError,
                                Converter={StaticResource TrueToCollapsedConverter}}">
    <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <Setter Property="IsExpanded" Value="True" />
        </Style>
    </TreeView.ItemContainerStyle>
</TreeView>

Here, unfortunately, is what it looks like. I've circled the blank areas, though really they're pretty obvious -- at least, the big block is; the little one could be mistaken for padding, but it's not.

Any thoughts? I can't get rid of that TextBlock because it's used by the DataTriggers, so I don't know what I'm missing here. And, it being my first time trying this, I'm not even sure where to start.

Update Here's the XML, by request:

<?xml version='1.0' encoding='UTF-8'?>
<DataUpdate>
  <EndpointId></EndpointId>
  <MessageId></MessageId>
  <UpdateList>
    <ChargeItem>
      <TenantId></TenantId>
      <PatientId></PatientId>
      <LastName></LastName>
      <FirstName></FirstName>
      <PatientGender></PatientGender>
      <EncounterId></EncounterId>
      <AttPhysicianId></AttPhysicianId>
      <AttPhysicianLast></AttPhysicianLast>
      <TransactionId></TransactionId>
      <TransactionDate></TransactionDate>
      <PostingDate></PostingDate>
      <TransactionCode></TransactionCode>
      <TransactionDesc></TransactionDesc>
      <TransactionAltDesc></TransactionAltDesc>
      <TransactionQuantity></TransactionQuantity>
      <TransactionAmount></TransactionAmount>
      <TransactionUnitAmt></TransactionUnitAmt>
      <DepartmentCode></DepartmentCode>
      <InsurancePlanId></InsurancePlanId>
      <InsuranceAmount></InsuranceAmount>
      <PatientLocation></PatientLocation>
      <FeeScheduleId></FeeScheduleId>
      <Patienttype></Patienttype>
      <DiagnosisCode></DiagnosisCode>
      <DiagnosisText></DiagnosisText>
      <DiagnosisCodeType></DiagnosisCodeType>
      <PerformedById></PerformedById>
      <PerformedByLast></PerformedByLast>
      <PerformedByFirst></PerformedByFirst>
      <OrderedById></OrderedById>
      <OrderedByLast></OrderedByLast>
      <OrderedByFirst></OrderedByFirst>
      <UnitCost></UnitCost>
      <FillerOrderNumber></FillerOrderNumber>
      <EnteredById></EnteredById>
      <EnteredByLast></EnteredByLast>
      <EnteredByFirst></EnteredByFirst>
      <ProcedureCode></ProcedureCode>
      <ProcedureCodeMod></ProcedureCodeMod>
      <NdcCode></NdcCode>
    </ChargeItem>
    <ChargeItem>
      <TenantId></TenantId>
      <PatientId></PatientId>
      <LastName></LastName>
      <FirstName></FirstName>
      <PatientGender></PatientGender>
      <EncounterId></EncounterId>
      <AttPhysicianId></AttPhysicianId>
      <AttPhysicianLast></AttPhysicianLast>
      <TransactionId></TransactionId>
      <TransactionDate></TransactionDate>
      <PostingDate></PostingDate>
      <TransactionCode></TransactionCode>
      <TransactionDesc></TransactionDesc>
      <TransactionAltDesc></TransactionAltDesc>
      <TransactionQuantity></TransactionQuantity>
      <TransactionAmount></TransactionAmount>
      <TransactionUnitAmt></TransactionUnitAmt>
      <DepartmentCode></DepartmentCode>
      <InsurancePlanId></InsurancePlanId>
      <InsuranceAmount></InsuranceAmount>
      <PatientLocation></PatientLocation>
      <FeeScheduleId></FeeScheduleId>
      <Patienttype></Patienttype>
      <DiagnosisCode></DiagnosisCode>
      <DiagnosisText></DiagnosisText>
      <DiagnosisCodeType></DiagnosisCodeType>
      <PerformedById></PerformedById>
      <PerformedByLast></PerformedByLast>
      <PerformedByFirst></PerformedByFirst>
      <OrderedById></OrderedById>
      <OrderedByLast></OrderedByLast>
      <OrderedByFirst></OrderedByFirst>
      <UnitCost></UnitCost>
      <FillerOrderNumber></FillerOrderNumber>
      <EnteredById></EnteredById>
      <EnteredByLast></EnteredByLast>
      <EnteredByFirst></EnteredByFirst>
      <ProcedureCode></ProcedureCode>
      <ProcedureCodeMod></ProcedureCodeMod>
      <NdcCode></NdcCode>
    </ChargeItem>
  </UpdateList>
</DataUpdate>