Wp7 Listbox Scrolling issue in PivotItem - Can't stay on very last item, fixed height does not help

Question

I have a simple listbox with more items than fit on the screen. If you scroll to the last item it is shown but then drops back off the screen - I can't leave it in view. After an hour of Googling it seems to be a known issue in early versions of the Listbox but it still seems to be the case in the latest tools. There also seems to be a problem with fixed heights and virtualization, but setting the height at item level or listbox level makes no difference. I see the Listbox in the WindowsPhoneDataBound app template works fine with scrolling and no heights.

I would also like a solution without fixed heights so that it does not require a new state for Landscape orientation.

Any suggestions please?

My listbox is in a usercontrol that is in a PivotItem:

        <controls:PivotItem x:Name="pivotItemSetup" Header="setup">
            <local:listBoxBlindsControl Margin="0,0,-12,0"/>
        </controls:PivotItem>

and the user control:

 <Grid x:Name="LayoutRoot" Background="Transparent">
        <ListBox x:Name="listBoxBlinds" ItemsSource="{Binding BlindSet.Blinds}" SelectionChanged="MainListBox_SelectionChanged" Height="500">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid Height="80" Margin="0,0,0,17" Width="103">
                        <StackPanel Orientation="Horizontal"  Visibility="{Binding IsBreak, ConverterParameter=true, Converter={StaticResource boolToVisibility}}" VerticalAlignment="Top" d:LayoutOverrides="Width">
                            <TextBlock Text="{Binding LevelNumber, ConverterParameter='level \{0\} - ', Converter={StaticResource stringTextConverter}}" TextWrapping="NoWrap" Margin="0" Style="{StaticResource PhoneTextExtraLargeStyle}" d:LayoutOverrides="Width"/>
                            <TextBlock Text="{Binding SmallBlind, ConverterParameter=\{0\}/, Converter={StaticResource stringTextConverter}}" TextWrapping="NoWrap" Margin="0" Style="{StaticResource PhoneTextExtraLargeStyle}" d:LayoutOverrides="Width"/>
                            <TextBlock Text="{Binding BigBlind}" TextWrapping="NoWrap" Margin="0" Style="{StaticResource PhoneTextExtraLargeStyle}" d:LayoutOverrides="Width"/>
                        </StackPanel>
                        <TextBlock x:Name="txtbreak" Text="break" TextWrapping="NoWrap" Margin="0,0,0,23" Style="{StaticResource PhoneTextExtraLargeStyle}" d:LayoutOverrides="Width, Height" Visibility="{Binding IsBreak, ConverterParameter=false, Converter={StaticResource boolToVisibility}}" Foreground="{StaticResource PhoneAccentBrush}" />
                        <StackPanel Orientation="Horizontal" Margin="0,0,0,23" VerticalAlignment="Bottom" d:LayoutOverrides="Width">
                            <TextBlock Text="{Binding MinutesPerBlind, ConverterParameter=\{0\} minutes, Converter={StaticResource stringTextConverter}}" TextWrapping="NoWrap" Margin="0" Style="{StaticResource PhoneTextSubtleStyle}" d:LayoutOverrides="Width"/>
                            <TextBlock Text="{Binding Ante, ConverterParameter=\, \{0\} ante, Converter={StaticResource stringTextConverter}}" TextWrapping="NoWrap" Margin="0" Style="{StaticResource PhoneTextSubtleStyle}" d:LayoutOverrides="Width" Visibility="{Binding Ante, ConverterParameter=0, Converter={StaticResource valueToVisibility}}"/>
                        </StackPanel>
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>

Some more info: I copied and pasted the exact XAML from the WindowsPhoneDataBoundApp (which works) into my usercontrol so that it now looks like this:

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
    <ListBox x:Name="listBoxBlinds" Margin="0,0,-12,0" ItemsSource="{Binding BlindSet.Blinds}" SelectionChanged="MainListBox_SelectionChanged">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Margin="0,0,0,17" Width="432">
                    <TextBlock Text="{Binding LevelNumber}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}"/>
                    <TextBlock Text="{Binding SmallBlind}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Grid>

and it does not work... so is it something to do with the PivotItem? Update: I took this code out of the PivotItem and it works fine.. so any ideas how to get it working in a pivotitem?