One the web I see there is a problem with a complex tooltip using a stackpanel in 3.5. -- The same code works fine in 4.0... 

here's the original code... 

<igDP:FieldLayout>
<igDP:Field Name="CompanyNameAreaName" Width="225" Label="Company - Office Location" Visibility="Visible" ToolTipService.ShowDuration="500000" Row="1" Column="1" >
<igDP:Field.Settings>
<igDP:FieldSettings>
<igDP:FieldSettings.CellValuePresenterStyle>
<Style TargetType="{x:Type igDP:CellValuePresenter}">
<Setter Property="FontSize" Value="10" />
<Setter Property="ToolTip" >
<Setter.Value>
<StackPanel>
<TextBlock Text="---- Tech Test Comment ---- " FontWeight="Bold" HorizontalAlignment="Center"></TextBlock>
<TextBlock Text="{Binding DataItem.TechTestComments}" TextWrapping="WrapWithOverflow" Width="300"/>
<TextBlock Text="---- Field Inspection Comment ----" FontWeight="Bold" HorizontalAlignment="Center"></TextBlock>
<TextBlock Text="{Binding DataItem.FieldInspectionComments}" TextWrapping="WrapWithOverflow" Width="300"/>
</StackPanel>
</Setter.Value>
</Setter>
</Style>
</igDP:FieldSettings.CellValuePresenterStyle>...

--- Here's what is supposed to be a work around -- but it just outputs "StackPanel"...

<igDP:XamDataGrid.Resources>

<StackPanel x:Key="resComments" >
<TextBlock Text=" Tech Test Comment " FontWeight="Bold" HorizontalAlignment="Center" />
<TextBlock Text="{Binding DataItem.TechTestComments}" TextWrapping="WrapWithOverflow" Width="300"/>
<TextBlock Text=" Field Inspection Comment " FontWeight="Bold" HorizontalAlignment="Center"></TextBlock>
<TextBlock Text="{Binding DataItem.FieldInspectionComments}" TextWrapping="WrapWithOverflow" Width="300"/>
</StackPanel>...

<igDP:FieldLayout>
<igDP:Field Name="CompanyNameAreaName" Width="250" Label="Company - Office Location" Visibility="Visible" ToolTipService.ShowDuration="500000" Column="0" Row="1" >
<igDP:Field.Settings>
<igDP:FieldSettings>
<igDP:FieldSettings.CellValuePresenterStyle>
<Style TargetType="{x:Type igDP:CellValuePresenter}">
<Setter Property="FontSize" Value="10" />
<Setter Property="ToolTip" Value="{StaticResource resComments}" />
</Style>
</igDP:FieldSettings.CellValuePresenterStyle>
</igDP:FieldSettings>
</igDP:Field.Settings>
</igDP:Field>...

--- is this an infragistics problem that I only get the string definition "System.Windows.Controls.StackPanel" under .net 3.5 for is this a more general problem? -- Any suggestions... again it works under 4.0

thanks